With control of the Senate likely to come down to a handful — or even a single — seat this November, party strategists are already beginning to handicap the 33 races up in 2006 as they jockey for the upper hand.

Unlike this cycle, where the playing field clearly tilted toward Republicans at the outset, neither side has an obvious advantage on paper.

Democrats must defend 17 states, Republicans 15, and Sen. Jim Jeffords (I-Vt.), who caucuses with Democrats, is also up for re-election.

Eight Democratic incumbents are standing for their first re-elections, however, including three — Sens. Maria Cantwell (Wash.), Mark Dayton (Minn.) and Debbie Stabenow (Mich.) — who won with less than 50 percent in 2000.

On the other end of the seniority spectrum, six Democrats up next cycle will be at least 70 years old and will have served at least two terms on Election Day 2006.

While none has signaled an intent to retire — and a few, like West Virginia Sen. Robert Byrd, are not expected to even consider leaving the chamber — the advanced age of the class worries some Democratic strategists.

For now, Senate Republicans are privately assuming that at least two of their seats will be open, as Majority Leader Bill Frist (Tenn.) and Sen. Trent Lott (Miss.) — Frist’s immediate predecessor in the post — are expected to leave.

Frist limited himself to two terms when he was first elected in 1994, and has shown no signs of backing away from that pledge despite his leadership position.

Many Republicans believe that Frist will leave the seat in 2006 and spend the next two years traveling the country and setting up a bid for president in 2008 when, regardless of the result this fall, the Republican nomination will be up for grabs.

Several Volunteer State GOPers are already angling for the nomination — led by 3rd district Rep. Zach Wamp.

Wamp, who faces no serious threat in his re-election bid in November, had raised more than $700,000 this cycle with $930,000 on hand at the end of April.

Wamp told a local paper in May that he planned to raise $1 million in each of the three remaining quarters of the year as he preps for the Senate race.

Other names mentioned on the Republican side include former 7th district Rep. Ed Bryant and Chattanooga Mayor Bob Corker.

Both men have run unsuccessful Senate primary bids in recent years.

Bryant lost by 11 points to now Sen. Lamar Alexander (R) in 2002; Corker lost a highly contentious 1994 primary to Frist by 12 points.

Freshman Rep. Marsha Blackburn (R) is also mentioned as a possible candidate.

For Democrats, Rep. Harold Ford Jr. is the odds-on favorite and has been running a behind-the-scenes campaign for the better part of the last four years.

Ford flirted with a challenge to Frist in 2000 before dropping out but will not pass on an open seat.

He raised $402,000 in the first three months of 2004, ending the period with $970,000 in the bank.

Chip Off the Old Lott

Although the race in Mississippi is less advanced, candidates are already angling to replace Lott if — as expected — he decides not to seek a fourth term.

Rep. Chip Pickering (R) would enter the contest as a heavy favorite.

Though he has not tipped his hand about any Senate intentions, most informed observers took Pickering’s decision not to accept a high-paying lobbying job last year as a sign he would make a bid for higher office.

Pickering has been a longtime Lott protege, having worked in his Senate office from 1990 to 1994.

Despite all of his strengths, Pickering ended March with just $70,000 on hand.

Democrats have had little luck in winning Senate seats in the Magnolia State in recent years though they believe that either former state Attorney General Mike Moore or former Gov. Ronnie Musgrove would be a strong candidate against Pickering.

Moore served as the state’s top cop from 1994 to 2002 and now heads up Partnership for a Healthy Mississippi, a nonprofit anti-tobacco organization.

He has often been courted to run in the past but demurred. It is not clear whether he would actually make the leap this time.

Musgrove was defeated in his bid for a second term by now-Gov. Haley Barbour (R) in 2003.

Though he took only 46 percent in that race, most Democrats in the state attributed the loss to Barbour’s solid campaign rather than any major flaw in the manner in which Musgrove conducted himself on the stump.

Two other Republicans —Sens. Kay Bailey Hutchison (Texas) and John Ensign (Nev.) — are mentioned as potential gubernatorial candidates in 2006.

Hutchison appears the more serious of the two about leaving the Senate, although she would have to challenge Gov. Rick Perry in a Republican primary.

Perry had dismal favorability ratings in a May survey conducted by Scripps Howard and is expected to face state Comptroller Carole Keeton Strayhorn (R) in a primary regardless of Hutchison’s ultimate decision.

Lt. Gov. David Dewhurst (R) is seen as a likely candidate if the Senate seat comes open; he actively considered running for the seat of retiring Sen. Phil Gramm (R) in 2002 before deciding to seek state office.

State Attorney General Greg Abbott and state Sen. Florence Shapiro are also mentioned as potential GOP Senate candidates.

On the Democratic side, the leading name is Rep. Jim Turner, who is retiring at the end of this session due to a Republican-led redistricting that left him without a seat to run in.

Ensign, who won an open seat in 2000, is reported to have some interest in the governorship in 2006, when Gov. Kenny Guinn (R) will be term-limited out.

Rep. Jim Gibbons (R) is considered the leading gubernatorial candidate, but would likely defer to Ensign, possibly even seeking the vacant Senate seat.

Six Septuagenarians

No current Democratic Senator has indicated that he or she will leave the chamber in 2006, but if one — or several — of a group that includes Byrd, Sen. Daniel Akaka (Hawaii), Edward Kennedy (Mass.), Dianne Feinstein (Calif.), Herb Kohl (Wis.), Paul Sarbanes (Md.) and Jeffords changed their mind it could drastically alter the playing field. All will be older than 70 in 2006.

Sarbanes has drawn the most speculation to this point, as he has yet to make an announcement on his re-election plans or raised much money; he will be 73 years old on Election Day 2006 and will have served 30 years in the Senate.

Kohl, Jeffords and Feinstein insist they are planning to run again while Byrd, Kennedy and Akaka are virtual institutions in the body and their home states.

In the event Sarbanes decides against a sixth term, a number of Democrats are mentioned as potential candidates including Baltimore Mayor Martin O’Malley (a more likely challenger to Republican Gov. Bob Ehrlich in 2006), former Rep. Kweisi Mfume as well as current 4th district Rep. Al Wynn and 7th district Rep. Elijah Cummings. Prince George’s County States Attorney Glenn Ivey, a former aide to Sarbanes and Senate Minority Leader Tom Daschle (S.D.), is also discussed as a candidate.

Lt. Gov. Michael Steele would be the favored Republican nominee in an open-seat scenario.

While Democrats currently have a slight edge in likely open-seat races, they have a much larger number of vulnerable incumbents.

Much of this vulnerability comes as a result of the party’s surprising four-seat pickup in 2000, which brought the Senate to parity — a balance tipped in Democrats’ favor when Jeffords left the Republican Party in May 2001.

Republican Targets

At the top of the Republican target list is Cantwell, who beat Sen. Slade Gorton by just more than 2,000 votes using $10 million of her own money — a loan largely secured by her stock in RealNetworks.

Following the burst of the Internet bubble, Cantwell found herself in massive personal debt.

At the end of March, Cantwell had repaid $7.8 million in loans and still owed $2.6 million. She had just $255,000 on hand.

The identity of the Republican contenders is not likely to be known until after this coming election.

National GOPers are high on both Rep. George Nethercutt, who is challenging Sen. Patty Murray (D), and former state Sen. Dino Rossi, the Republican frontrunner in the open seat governor’s race.

If one or both come up short this time, expect Republicans to look to one of them as the preferred candidate against Cantwell.

If Cantwell is the most vulnerable Democratic Senator, Dayton is not far behind.

Another self-funding candidate, Dayton defeated freshman Sen. Rod Grams (R) in 2000 but has kept an extremely low profile since coming to the Senate.

Already Rep. Mark Kennedy (R) has made noise about challenging Dayton and Republicans believe he would make an extremely strong candidate.

House Democrats seem intent on ensuring that Kennedy doesn’t use the remainder of this cycle to raise money for a Senate bid. They recruited well-known children’s safety advocate Patty Wetterling (D) to run against Kennedy, though it is an uphill fight given the 6th district’s Republican lean.

Though Democrats admit Dayton is vulnerable, his vast personal wealth is a major asset.

The third member of the “49 percent” club — Stabenow — appears to be in stronger shape.

One name mentioned is 7th district Rep. Nick Smith (R), who is retiring this year after six terms.

Republicans are more confident about their chances against Sens. Ben Nelson (Neb.) and Bill Nelson (Fla.), both of whom won open seats with 51 percent.

Gov. Mike Johanns (R) is seen as Republicans’ strongest potential candidate in Nebraska, but has said he will not make a decision until 2005.

In Florida, Rep. Katherine Harris (R) passed on this year’s open seat Senate race with an eye toward challenging Nelson in 2006.

She gained a national profile for her role in the 2000 Florida presidential recount when she served as secretary of state.

Harris had $821,000 in the bank at the end of March; Nelson had $1.7 million.

Both Democratic Senatorial Campaign Committee Jon Corzine (N.J.) and New York Sen. Hillary Rodham Clinton had relatively close races in 2000 but present elusive targets for Republicans due to their financial strength.

Corzine, a former Goldman Sachs executive, spent more than $60 million of his own money to win the Garden State open seat in 2000 with 50 percent. He has said he will again dip into his wealth to fund his re-election campaign.

Former Jersey City Mayor Bret Schundler and 2002 Senate nominee Doug Forrester are mentioned as Republican candidates.

Clinton tapped into the vast national fundraising network she developed along with her husband to raise and spend better than $41 million in her defeat of then Rep. Rick Lazio (R) with 55 percent.

Republicans pine for former New York City Mayor Rudy Giuliani to challenge Clinton but that seems an unlikely prospect as he appears more interested in a gubernatorial or presidential race.

Gov. George Pataki is not expected to seek a fourth term in 2006 but is likely to begin laying the groundwork for a 2008 presidential run rather than launching a campaign for the Senate.

Democratic Opportunities Limited

Fewer Senate Republican incumbents are currently seen as endangered.

Democrats are, however, salivating at the chance to take on Sen. Rick Santorum (R-Pa.), one of the most vocal conservatives in the body.

Keystone State Treasurer Barbara Hafer (D) is seen as the most likely candidate; she switched parties in late 2003 following her support for Gov. Ed Rendell (D) in his 2002 contest.

Rep. Joe Hoeffel’s challenge to Sen. Arlen Specter (R) this fall has widely been perceived as a set-up race for a challenge to Santorum.

State Sen. Connie Williams (D) turned down a race for the 6th district this cycle but might be interested in a Senate race in 2006. She has significant personal wealth.

Current National Republican Senatorial Committee Chairman George Allen (Va.) could face a serious challenge if Gov. Mark Warner (D) decides to run. (See related story, p. 23.)

Warner is term-limited in 2005 and ran a surprisingly strong challenge to Sen. John Warner (R) in 1996 fueled by personal donations.

Democrats also believe that Arizona Sen. Jon Kyl (R) can be defeated though he was unopposed by a major party candidate in his 2000 re-election race.

State Democratic Party Chairman Jim Pederson, a real estate developer who brings the ability to self-fund the race, is the most oft-mentioned candidate.