Eleven Senators up for re-election in 2004 raised more than $1 million in the second quarter of this year and 14 banked more than $2 million.

Self-funding candidates continued to populate the upper echelon of fundraisers, led by free-spending Illinois businessman Blair Hull (D), who chipped in $4 million of his own money in the period and spent almost $2 million, more than any other candidate — challenger or incumbent.

With the field almost to himself and potential Democratic contenders awaiting a decision about re-election from Sen. John Edwards (D), Rep. Richard Burr (R-N.C.) posted another impressive quarter, raising $1.5 million and banking nearly $3.5 million.

Campaigns were required to submit the reports, which cover contributions and expenditures from April 1 to June 30, to the Federal Election Commission no later than midnight Tuesday.

Most incumbents facing even a hint of electoral difficulty moved aggressively to amass huge war chests, hoping to force would-be opponents to think twice about making a race.

On the Democratic side, Sen. Charles Schumer (N.Y.) continued to have the biggest war chest, with approximately $16.5 million in the bank. His aides could provide no further details Wednesday evening.

Sen. Barbara Boxer (D-Calif.) raked in $1.7 million in the quarter and finished June with nearly $3.2 million in cash on hand. Boxer’s only announced opponent, former Los Altos Hills Mayor Toni Casey (R) raised $317,000 and ended with $289,000 in reserve. Former U.S. Treasurer Rosario Marin (R), who is expected to challenge Boxer, has not yet begun to raise money.

Sens. Tom Daschle (D-S.D.) and Harry Reid (D-Nev.) also put together strong second-quarter showings as they await decisions from a former and a current GOP House Member, respectively, about possible challenges.

Daschle brought in $1.4 million between April 1 and June 30 with $2.9 million remaining in his campaign coffers.

Former Rep. John Thune (R), who lost a 2002 race to Sen. Tim Johnson (D), is expected to challenge Daschle but has not yet formed a campaign committee.

In Nevada, while Rep. Jim Gibbons (R) continues to ponder a race against Reid, the incumbent is seeking to turn the potential contest into a financial mismatch. Reid raised $1.2 million in the quarter to Gibbons’ $129,000. The Nevada Senator banked $3.1 million, roughly $2.6 million more than Gibbons had in the bank at 2003’s halfway mark.

Gibbons said Wednesday he will make a decision on the race by the “latter half of August.” He is also mentioned as a candidate for the state Supreme Court.

On the Republican side, several targeted Senators are taking advantage of the lack of a top-tier Democratic challenger to solidify their financial standing.

Sen. Kit Bond (Mo.) raised an impressive $1.7 million in the period, boosting his reserves to $2.8 million. Senate Democrats continue to believe they can beat Bond, but have seen state Auditor Claire McCaskill as well as Lt. Gov. Joe Maxwell pass on the race; Maxwell cited Bond’s fundraising ability as his primary reason for bowing out.

State Treasurer Nancy Farmer is the latest Democratic recruiting target in the Show Me State. She raised $776,000 for her successful 2000 race.

In Kentucky, Bunning appears to be capitalizing on the uncertainty surrounding the identity of the eventual Democratic nominee, bringing in $991,000 over the past three months and holding just more than $2 million in his war chest.

Bunning was seen as one of the most vulnerable GOP Senators this cycle but caught a major break when Democratic Gov. Paul Patton (Ky.), an all-but announced Senate candidate, saw his political career destroyed by revelations that he had carried on an extramarital affair with a state employee.

With so much focus in the Bluegrass State on this year’s gubernatorial race, Democrats have yet to recruit a top challenger. Former state Attorney General Fred Cowan (D) is the only announced candidate; he ended June with $172,000 on hand.

One Republican who did not take advantage of the absence of a strong opponent was Sen. Ben Nighthorse Campbell (Colo.), who showed a disappointing $499,000 raised, several hundred thousand dollars less than he had predicted he would raise just days ago. Democrats have yet to recruit a credible foe, although Rep. Mark Udall (D) has not entirely ruled out a challenge.

Illinois seems poised to witness an orgy of spending in the wide-open race to replace retiring first term Sen. Peter Fitzgerald (R). Aside from Hull, former Goldman, Sachs & Co. executive Jack Ryan (R) donated $1 million out of his own pocket in the quarter. Because of the so-called “millionaires amendment” included in the Bipartisan Campaign Reform Act passed last year, Democrats running against Hull were eligible to take donations from individuals in chunks as large as $12,000 due to the magnitude of his personal giving; Ryan’s opponents were allowed to take $6,000 checks.

In South Carolina, where Sen. Fritz Hollings (D) looks increasingly likely to retire, GOP contender Thomas Ravenel loaned his campaign $950,000 in the period, allowing Rep. Jim DeMint and former state Attorney General Charlie Condon, the other candidates in the Republican primary, to receive $6,000 contributions. If Ravenel’s personal giving exceeds $1,076,000, both DeMint and Condon will be able to accept $12,000 checks.

DeMint, who began the year as the frontrunner for the GOP nod, raised $592,000 for the quarter and banked $811,000. Condon raised a surprising $451,000.

All three potential Republican candidates outraised Hollings, who brought in just $106,000. He has raised just $172,000 this year, although he ended June with a healthy $970,000 in the bank. A number of Hollings’ Democratic colleagues are also contemplating retirement and their fundraising numbers will do little to quiet the rumor mill.

Sen. John Breaux (La.) raised $386,000 over the last three months, a total greater than only Hollings and Sen. Daniel Inouye (Hawaii) among Democrats.

The Louisiana Senator remains undecided on re-election and is not expected to announce a decision until the 2003 Pelican State gubernatorial race concludes in November.

Meanwhile, Reps. David Vitter (R-La.) and Chris John (D-La.), the odds-on nominees for their respective parties in an open-seat situation, continued to stockpile funds. Vitter, a prolific fundraiser, took in $246,000 and put away $1.1 million. John outraised Vitter in the period by $7,000 but finished with almost $400,000 less in the bank.

In both North Carolina and Florida, the incumbent Democratic Senators devoted almost all of their fundraising energies to their presidential bids.

Edwards, who has raised nearly $12 million for the White House sweepstakes, brought in only $5,000 to his Senate committee. He did retain $1.4 million on hand, however.

Some Democrats have grumbled that while Edwards remains on the fence about a second term, Burr is taking advantage of the void to make inroads with Democratic givers. Already two men who held fundraisers for 2002 Senate nominee Erskine Bowles (D) have done events for Burr.

Graham raised $3 million for his presidential committee in the quarter; his Senate account showed $243,000 on hand.

Republicans have far fewer retirement possibilities, with Sen. Don Nickles (Okla.) far and away the most likely at this point.

Nickles’ $339,000 total puts him second from the bottom on the GOP tote board (Idaho Sen. Mike Crapo raised $262,000) and is likely to give continued speculation that he will call it quits at the end of his fourth term.

Nickles is not expected to make a decision until late in the fall and has even suggested he might wait until the Easter holiday next year to make an announcement.

In preparation for a possible open seat, Reps. Brad Carson (D) and Ernest Istook (R) increased their fundraising activity over the last three months.

Istook raised $329,000 and Carson $183,000. Neither were able to match Nickles’ $744,000 on-hand total, however. Istook had $306,000 when the books closed; Carson banked $191,000.

Josh Kurtz, Sarah Bouchard, Chris Wright and Paul Kane contributed to this report.