Election season has almost reached its costly, bitter end, but the spigot of money that runs from PACs and special interests to federal campaigns is still running. We’ve taken a look at where the late money is going in House races and found some incumbents in supposedly safe districts fundraising as if their races are closer than they would like them to be.

Other members on our list seem to be raising cash with an eye to future endeavors. For candidates cruising to victory, a surplus of campaign cash can be a handy way to win friends and influence among another key constituency: colleagues in the House. By making donations to the national party or fellow lawmakers in more competitive districts, members can earn the chits they will need to win a role in party leadership or a plum committee assignment in the next Congress.

Wealthy candidates in tight races who are providing late financing to their own campaigns lead our list of late fundraising hauls, which we compiled from candidates’ 48-hour reports, posted to the Federal Election Commission as of Friday afternoon. These document the large contributions ($1,000 or more) candidates receive in the final 20 days before an election. The self-funders include ophthalmologist Nan Hayworth in New York and developer-turned-congressman Doug Ose in California. Others topping the list include candidates in highly competitive races for open House seats.

Who’s getting the most last-minute money?

What’s interesting and revealing are the surprises: In Nevada’s sprawling 4th District, which includes part of North Las Vegas and much of the southern portion of the state, help is parachuting in for incumbent Rep. Steven Horsford, who’s on the ropes against insurgent Republican challenger Cresent Hardy.

Horsford has leaned on his Democratic compatriots in the home stretch. He pulled in $37,000 from other Democrats in the past two weeks, got a radio endorsement from Barack Obama, and has been fêted by House Democratic Leader Nancy Pelosi, as shown by this invitation derived from Sunlight’s Political Party Time:

Reception

It has been an assortment of political action committees, however, that have put the most in to the incumbent’s campaign over that time, combining for $107,000 all told. If Horsford manages to keep his seat, it will be in no small part to the last-minute assistance of long-time Democratic allies; this includes AFSCME, the government workers’ union, which kicked in $4,000, the International Association of Firefighters’PAC ($4,000), the PAC of the Service Employees International Union ($3,000) and a host of others.

Some 1,800 miles away in the southwest corner of Michigan, Republican Rep. Fred Upton is also getting a late-breaking special interest cash infusion.

Upton has been on a fundraising tear since late-breaking polls indicated his Democratic challenger, Paul Clements, is cutting in to his lead. Upton raised $245,000 in the past two weeks alone, $208,000 of which came from PACs.

As chairman of the Energy and Commerce Committee, he’s one of the most powerful Republicans in the House. But Michigan’s 6th District, which Upton represents, has trended purple in recent presidential elections. Moreover, political reform group MayDay PAC has pumped $1.8 million in to the race for Hardy. That outlay has gotten the attention of Upton allies. The Huffington Post reported Oct. 20 that an Energy Committee staffer had been calling and chastising some of MayDay PAC’s backers in the tech industry after the group went after Upton.

Upton’s committee perch has made him a magnet for contributions from the industries he regulates. Recent donations from the political committees of groups like General Motors ($5,000), the American Council of Engineering Companies ($5,000) and Peabody Energy ($5,000) indicate they don’t want to see the 20-year House veteran leave.

It’s this cozy relationship between Upton and Washington PACs that led MayDay to enter the race in the first place.

But while this last-minute push for cash from Horsford and Upton screams “panic mode,” other candidates on our list aren’t facing similar danger. Some, like Republican Rep. Gregg Harper of Mississippi, don’t even have a challenger.

Harper’s re-election cakewalk hasn’t slowed down his campaign’s fundraising; however, he’s raised $120,000 in the period we analyzed. Unlike the other members mentioned in this story, Harper got most of that money from wealthy individuals in his home state.

And then there’s Donald Norcross, a veteran New Jersey state senator (and brother of longtime Jersey Democratic boss George Norcross, majority owner of the Philadelphia Inquirer), running for an open seat in his state’s 1st District. Having raised 20 times more money than his Republican opponent for a seat that’s rated safe Democrat, Norcross should be cruising to victory. Nonetheless, he’s receiving thousands of big, late checks from union and corporate PACs, as well as hundreds of thousands of dollars worth of help from the House Majority PAC, a super PAC that has been underwritten by six- and seven-figure checks from labor unions and major Democratic donors.

If the 114th Congress sees Harper and Norcross climbing leadership ladders in their respective parties, they’ll know whom to thank.