Freshman Democratic Senators — who benefited from millions of dollars in political action committee donations in the 2006 elections — have wasted little time revving up their own leadership committees to help boost candidate and party efforts.

Newly filed fundraising reports show most of the freshmen raised modest amounts for their PACs in the first six months of 2007. However, their early giving patterns reveal that it didn’t take long for the new Senators to realize the value of having an extra financial vehicle to help their party retain and grow its majority.

Six of the newcomers have given a total of $83,500 from their PACs to the Democratic Senatorial Campaign Committee, and most contributed directly to the re-election campaigns of their fellow Senators, especially Sen. Tim Johnson (S.D.).

All but one of the 11 freshman Senators have PACs — including the four former House Members who arrived in January with their committees already operational. Sen. Bob Casey (Pa.) is the only holdout who has not formed one yet.

Sen. Jim Webb (Va.), whose defeat of then-Sen. George Allen (R) in November is credited with flipping control of the chamber to Democrats, blew away his freshman colleagues when it came to PAC fundraising in the first six months of the year.

Webb raised $230,000 for his Born Fighting PAC, including $41,000 from interest groups and $30,000 in conduit contributions through ActBlue, an Internet-based fundraising effort that funnels money to progressive Democratic candidates.

Webb had $117,000 in his PAC account as of June 30, more than any other freshman Senator.

While he spent liberally in the first half of the year, his only donation to support federal candidates was a $5,000 check to the DSCC. He also gave close to $20,000 total to 17 Democratic candidates running for the Virginia House of Delegates and state Senate this fall.

Sen. Amy Klobuchar (Minn.) was the second-most active fundraiser behind Webb, bringing in $116,000 for her Follow the North Star Fund through June 30.

Of that total, she gave $26,000 to Democratic candidates and causes, including $15,000 to the DSCC. She also sent checks to the re-election campaigns of Sens. Tom Harkin (Iowa), Mary Landrieu (La.) and Johnson, who has not returned to the Senate since suffering a brain aneurysm late last year.

Sen. Sherrod Brown (Ohio), a seven-term House Member who defeated then-Sen. Mike DeWine (R), raised $92,000 in six months, a little more than the combined total his PAC raised in 2005 and 2006. He has operated his America Works PAC for 10 years.

Brown’s PAC raised $42,500 from interest group PACs and $15,000 in conduit contributions from ActBlue.

He gave $15,000 to the DSCC and donated $5,000 to Johnson. He also sent checks to his two former House colleagues seeking to join him in the Senate: Rep. Tom Allen (D-Maine), who is challenging Sen. Susan Collins (R), and Rep. Mark Udall (D), who is running for an open Colorado Senate seat.

Montana Sen. Jon Tester raised the least of all the freshman Senators who filed reports. He collected just $7,700 in six months, and $2,500 of that total was a donation from fellow Montana Democratic Sen. Max Baucus’ Glacier PAC. Tester has not given to any party candidates or causes.

By contrast, Sen. Sheldon Whitehouse (R.I.) was the most generous of all freshmen with his PAC donations.

Whitehouse, who knocked off Sen. Lincoln Chafee (R) in the previous cycle, raised $45,000 in six months and gave almost $47,000 to aid Democratic candidates.

He gave $28,500 to the DSCC and also contributed $4,600 each to Allen, Johnson, Landrieu and Sen. Jack Reed (R.I.).

Leadership PACs traditionally were formed and used by party leaders — and those who wanted to become leaders — to spread money around to candidates and curry favor with incumbents. But in recent years they have increasingly become a more common vehicle for rank-and-file House and Senate Members to aid their colleagues’ re-elections.

Incumbents can give up to $10,000 — $5,000 for the primary and $5,000 for the general election — to other candidates through their PACs, whereas through their personal campaign committees they are limited to giving a $4,000 maximum contribution per cycle.

There also are higher individual contribution limits for PACs compared to campaign committees. Members can accept up to $10,000 each election cycle from individuals for their PACs, while they can receive up to $4,600 per cycle from individuals for their re-election campaign.

Sen. Claire McCaskill (Mo.) raised $23,500 for her PAC in the first six months after taking office. All of that total came from individuals.

She didn’t spend much, but she did give $4,600 to former Kansas City Mayor Kay Barnes, a top Democratic recruit who is challenging Rep. Sam Graves (R-Mo.).

Sen. Benjamin Cardin’s (Md.) LEGPAC raised $46,000 from January 1 to June 30, with all but $5,000 coming from interest groups’ PACs.

In late June, Cardin gave $5,000 to the DSCC and $1,000 to Johnson’s re-election campaign.

Sen. Bob Menendez (N.J.), a former party leader in the House appointed to the Senate in 2006, has raised $22,000 so far this year through his New Millennium PAC. He gave $15,000 to the DSCC in late June.

Though Casey has not formed a PAC, he nonetheless has contributed to his party’s collective election efforts, transferring $50,000 from his Senate campaign account to the DSCC in January.

Sen. Bernie Sanders (I-Vt.), another former House Member, has a PAC but doesn’t appear to be keeping up with reporting deadlines for it.

Sanders’ last report to the Federal Election Commission for his Progressive Voters of America PAC was his 2006 October quarterly report. Since May of last year he has received five notices of failure to file from the FEC.

Sen. Bob Corker (Tenn.), the lone Republican in the 2006 class, just filed paperwork to initiate his Rock City PAC one month ago and has not yet reported any fundraising.