While next year’s elections offer the Democrats a chance to retake the Senate and the Republicans an opportunity to get to a filibuster-proof 60-seat majority, neither party will likely make such dramatic gains in November 2006. [IMGCAP(1)]

Retirements, of course, could change the arithmetic of next year’s Senate elections, and candidate recruitment is always an important factor in any election cycle. But at least at this early date, few Senate races are currently in play — or are likely to be in play.

Any midterm election offers the party not holding the White House an opportunity to ride a wave. That’s especially true when one party holds both chambers of Congress and the White House. So a Democratic wave is possible, though not, at this point, visible on the horizon.

Only three 2006 Senate contests currently appear likely to go down to the wire.

The biggest race of the cycle looks to be in Pennsylvania, where Sen. Rick Santorum (R) faces a nightmare challenge from state Treasurer Bob Casey Jr. (D).

Republican strategists emphasize that Santorum is a good campaigner and has the advantages enjoyed by any incumbent, but they also privately acknowledge that Casey presents the Republican Senator with an extremely difficult problem. They see the challenger as uniquely able to hold onto the blue collar, socially conservative Democrats who have defected to GOP candidates in the past.

Many media reports have already noted that Santorum is emphasizing more moderate positions as he tries to appeal to less conservative voters. But some veteran GOP operatives think that’s a losing strategy.

“Santorum needs to make his race against Casey into the Helms-Hunt race of 1986,” one Republican insider argued. That race turned into a bloodbath, with Sen. Jesse Helms (R-N.C.) surviving against favored Gov. Jim Hunt (D). Both well-known politicians ended the campaign with extremely high negatives.

The difference, of course, is that Santorum represents Pennsylvania in the Senate, not North Carolina, so a bloodbath in the Keystone State could leave Casey as the winner.

The next mega-race is in Minnesota.

Regardless of whether you believe Sen. Mark Dayton’s (D) retirement enhances Democrats’ chances of holding the seat, it’s clear Republicans have a good opportunity.

Minnesota has become a tossup in both state and federal races, and neither party has an established star who would start as a solid favorite in the race.

As in Pennsylvania, where Democrats have united behind the candidacy of Casey, most Republicans in Minnesota have lined up behind Rep. Mark Kennedy’s bid.

Former Sen. Rod Grams (R), who lost to Dayton in 2000, says he, too, is in the race for the GOP nomination. But Grams didn’t distinguish himself either as a Senator or as a candidate, and Minnesota Republican insiders aren’t about to support his bid.

The third excellent race features Rhode Island Sen. Lincoln Chafee (R).

Chafee faces the possibility of a primary from conservative Cranston Mayor Steve Laffey. While incumbents are nearly unbeatable in a primary, that wouldn’t at all be the case next year in the Ocean State. Given Chafee’s moderate bent, and the fact that the Senator declined to vote for an incumbent Republican president in the last election, Laffey would be the favorite in that primary.

Even if Chafee wins renomination, he faces a serious challenge in the general, whether from Secretary of State Matt Brown or unsuccessful 2002 gubernatorial primary hopeful/ex-state Attorney General Sheldon Whitehouse.

Other potential takeovers, of course, could develop during the next 19 months.

An open seat in Tennessee gives Democrats a takeover opportunity, but the GOP begins with the edge. A Senate bid by outgoing Gov. Mark Warner (D) would make Virginia very interesting, though he is not expected to run.

Strong GOP recruits in Michigan, Florida, Maryland and Washington could make those Senate races very competitive, as would strong Democratic challengers in Missouri, Ohio and possibly Maine. But the early signs in all six of those states are not particularly encouraging. Still, one or two are likely to be worth watching by the time next year rolls around.

If you are looking for lower-profile contests that could develop into top-tier races, both Montana and New Jersey are worth a long look.

Sen. Conrad Burns (R-Mont.) has won three times, but his only comfortable win was in 1994, the best Republican year in my lifetime. Burns is one of those Senators who seemingly can’t stand success. He could well get himself into trouble again, and the current controversy over his relationship with tainted GOP lobbyist Jack Abramoff is a case in point. A credible Democrat could easily put this race into play.

And in the Garden State, where Republican candidates in statewide races have flopped for years, the GOP could make a run. Everything, of course, depends on whom soon-to-be-Gov. Jon Corzine (D) appoints to fill his soon-to-be-open Senate seat, and whom the party nominates next year. It also depends on whether New Jersey Republicans are astute enough to nominate state Sen. Tom Kean Jr. for the Senate.

There are plenty of surprises still to come in the ’06 Senate cycle. But for now, it’s hard — no, impossible — to see the Democrats regaining the majority next year.

Stuart Rothenberg is editor of the Rothenberg Political Report.