While the 2008 Senate playing field is far from developed, first-quarter fundraising reports filed this week offered early insight into just how fluid the competitive terrain remains and how important recruiting efforts will be to both parties’ chances for success.

At least 10 of the 32 Senators up for re-election in 2008 raised more than $1 million in the three-month period, Federal Election Commission reports show. But of that group only two are certain to have difficult re-election races: Sens. Mary Landrieu (D-La.) and Norm Coleman (R-Minn.). Both Senators represent states that lean in the opposite direction of their respective political parties, especially in presidential election years.

Landrieu raised a little more than $1 million in the period as she girds for a likely high-profile battle next year against a yet-to-be determined opponent. Several Republicans have been mentioned as possible candidates, including Rep. Richard Baker (R-La.), who has indicated he is considering the race.

But as Landrieu’s report showed she had close to $1.9 million in the bank on March 31, there was little on Baker’s report to indicate he is gearing up to run. Baker, who has close ties to the financial services industry, raised $113,000 in the quarter and he had just $66,000 in his campaign account at the end of the period.

In Minnesota, Coleman raised $1.5 million and his campaign war chest had swelled to $2.8 million by the end of the quarter.

The new reports also confirmed that Coleman’s first re-election contest will be one of the costliest of the cycle.

Comedian and talk show host Al Franken (D), who launched his Senate campaign in February, was able to raise more than $1.3 million in the quarter, by far the highest total for any of the announced challengers in 2008.

But Franken faces a primary against wealthy trial attorney Mike Ciresi (D), who plans to formally announce his candidacy this week. Ciresi spent some $5 million in his attempt to win the Democratic-Farmer-Labor Senate nomination in 2000, but he finished second in the Democratic primary with 22 percent of the vote.

Many other Senators who raised more than $1 million in the period did so to bolster efforts to scare off potential challengers.

Democratic Sens. Mark Pryor (Ark.), Max Baucus (Mont.) and Tom Harkin (Iowa) all are viewed as potentially vulnerable if top-tier candidates were to run against them. But in each case, none appear to be on the horizon.

Rep. Denny Rehberg (R-Mont.) remains Republicans’ best hope for generating a competitive contest against Baucus. But the Congressman raised just $82,000 in the quarter, a strong indication that he isn’t looking to make a move against Baucus.

Pryor raised the second-most of all incumbent Senators up for re-election in 2008, behind Sen. John Kerry (D-Mass.), who used his stature as the 2004 Democratic presidential nominee to remain far ahead of the rest of the field.

Kerry raised $7.6 million in the quarter and had a little more than $6 million in cash on hand at the end of the period.

Pryor took in close to $1.8 million and showed more than $2 million in the bank. There is little talk of a credible challenger to Pryor emerging, unless former Arkansas Gov. Mike Huckabee (R) reverses course and decides to run for Senate instead of continuing his 2008 presidential campaign.

Among Republicans, a trio of first-term Senators used the first quarter to continue building huge war chests — money that party leaders could covet down the stretch if the Senators end up not having difficult races of their own.

Currently, GOP Sens. John Cornyn (Texas), Saxby Chambliss (Ga.) and Lindsey Graham (S.C.) all look like solid bets for re-election next year, with little to no talk of competitive Democratic challengers emerging.

For the quarter, Cornyn raised $984,000 and had $3.8 million in the bank; Chambliss raised $831,000 and had $2.8 million in cash on hand; and Graham raised $1.2 million and had more than $3.7 million left in reserve.

Conversely, Republican Sens. Susan Collins (Maine), John Sununu (N.H.) and Gordon Smith (Ore.) appear to be particularly vulnerable in the Democratic-leaning states they represent because of the current political climate.

All three Senators ended March with more than $1 million in their war chests — Smith, who is personally wealthy, had more than $2 million — as Democrats actively are seeking to woo top-tier opponents to run against them.

In Maine, Rep. Tom Allen (D) is expected to challenge Collins. Allen raised $393,000 in the quarter and showed more than $800,000 in the bank.

In New Hampshire, several Democrats have lined up to take on Sununu, but the candidate that national party leaders want — former Gov. Jeanne Shaheen (D) — has yet to toss her hat into the ring.

Sununu raised $546,000 in the period and had $1.2 million on hand. Katrina Swett (D), the wife of former Rep. Dick Swett (D-N.H.) and one of the Democrats running to challenge Sununu, raised $462,000 and had a little less than that on hand.

In Oregon, Democrats are having a more difficult time finding a candidate to challenge Smith. The two-term Senator raised $748,000 and had more than $2.8 million on hand at the end of March.

After a recent poll done for the Democratic Senatorial Campaign Committee showed Rep. Peter DeFazio (D) ahead of Smith in a hypothetical matchup, the Congressman said he is contemplating making the race.

DeFazio, presumably with the backing of national party leaders, should have little trouble raising big money if he decides to run. But at the end of March he showed just $106,000 in the bank after raising a meager $25,000 in the first quarter.

Democrats also are looking to recruit a candidate to challenge Sen. Elizabeth Dole (R-N.C.) next year, and Rep. Brad Miller (D-N.C.) said he is considering running after polls showed Dole potentially vulnerable.

However, Dole turned in one of the most noteworthy first-quarter fundraising performances by taking in close to $1.8 million. Miller, who only last week revealed that he has talked to the DSCC about possibly running, raised $107,000 and had $77,000 in cash on hand at the close of the quarter.

Similarly, Democrats would like to find a top-flight candidate to challenge Senate Minority Leader Mitch McConnell (R) in Kentucky. McConnell raised $1.7 million and had more than $4.3 million at his disposal at the end of March. He may face wealthy businessman and frequent candidate Charlie Owen (D) next year.

With Republicans defending 21 seats in 2008, Democrats are largely playing offense. But aside from Louisiana, the other potential trouble spot for Democrats is in South Dakota, where Sen. Tim Johnson (D) still is recovering from brain trauma but preparing to run for re-election.

With help from his colleagues, Johnson raised $665,000 in the period and had $1.2 million in cash on hand for his campaign.

Republicans are looking for Gov. Mike Rounds (R) to run, but Rounds has not yet signaled what he will do.

Meanwhile, in the only open-seat contest to date, Rep. Mark Udall (D-Colo.) raised $335,000 in the quarter for his bid to succeed retiring Sen. Wayne Allard (R-Colo.). The Democratic establishment has rallied behind the Congressman, who showed more than $1.5 million in cash on hand at the end of March. The Republican field, meanwhile, remains unclear after former Rep. Scott McInnis (R) recently announced that he would not run.

First-quarter fundraising in the off-election years often gives both parties a fresh glimpse of possible retirements looming on the horizon.

In Virginia, all eyes are on Sen. John Warner (R), who turned in one of the poorest fundraising showings of all time in the first quarter by raising a mere $500.

Warner has indicated that he’s preparing to run again, but he won’t make a decision until later this year. If he does run, he is not expected to face a vigorous challenge.

Several candidates are waiting in the wings to jump into an open-seat contest, with Rep. Tom Davis (R) chief among them.

Davis raised $624,000 in the period and showed $833,000 in the bank on March 31. Other Republicans in the delegation may look at the race if Warner retires, as would former Gov. Jim Gilmore (R) and former Sen. George Allen (R).

Sen. Pete Domenici (R-N.M.) also has been high on the list of possible GOP retirements, even though he has said he is running again. The Senator raised $395,000 in the period, one of the smallest amounts among those up next year. Domenici had $541,000 in cash on hand.

Rep. Heather Wilson (R-N.M.), who likely would run to succeed Domenici if he retires, raised almost as much as the Senator did, taking in $325,000. Democrats have targeted both Wilson and Domenici recently over their role in the controversy surrounding the U.S. attorney firings.

The only other incumbent on retirement watch, Sen. Thad Cochran (R-Miss.), posted strong numbers for the quarter signaling he is indeed preparing to run again. The five-term Senator and ranking member of the Appropriations Committee raked in $633,000 and had $896,000 in cash on hand.

Marnette Federis and Jamie Weinstein contributed to this report.