Other than that whole "not blogging on weekends" thing, the best part of the six-week lull before the next presidential primary is that the candidates will actually have some time to serve their home-state constituents--also known as, um, "doing their jobs."

Today, for example, none of the remaining candidates--Barack Obama, Hillary Clinton or John McCain--is stumping in Pennsylvania or fundraising in Manhattan. Instead, they've all decided to visit a curious, off-the-beaten-path hamlet known as Washington, D.C. to vote on the 2009 budget resolution. Fancy that.

Not that the good people of Arizona, Illinois and New York are, you know, the real reason our three White House hopefuls have returned to the swamp. That would be--you guessed it--presidential politics. The key item on the agenda is a measure designed to ban congressional earmarks for one full year. (UPDATE, March 14: And if anyone was confused about their idiosyncratic motives, a quick glance at last night's roll call would clear things up--a 71-29 vote against the amendment, with only three Democrats joining Clinton and Obama to vote "yea.")

The legislation is McCain's baby. Proud recipient of the top Senate score from the earmark watchdogs at Citizens Against Government Waste, he's long railed against "wasteful pork-barrel spending" and pledged to "veto every single pork-barrel bill Congress sends me" if elected president. So the opportunity to co-sponsor the proposed ban was too good to pass up. Not only does McCain burnish his anti-pork cred, but he can also loudly contrast himself with Clinton and Obama, neither of whom have opposed earmarks as strongly in the past. "I call on my Democratic colleagues... [to] make this a bipartisan effort to return the budget to a focus on genuine national priorities," he said last week. "And, in the spirit of openness and transparency in government, I call on them to fully disclose all of their earmark requests while serving in the U.S. Senate." Translation: meet me in November.

Unwilling to cede any general-election ground, both Clinton and Obama have since declared that they support McCain's amendment--unlike, say, senate majority leader Harry Reid, who is reportedly not running for president. McCain quickly put out a statement "praising" them for their  “new-found enthusiasm” on earmarks. But the shift is a little less jarring for Obama than Clinton. In the Senate, Obama worked closely with Sen. Tom Coburn (R-Okla.) to draft and pass the Federal Funding Accountability and Transparency Act, which increases transparency by "by creating a user-friendly website to search all government contracts, grants, earmarks and loans." And he sponsored a bill (the Transparency and Integrity in Earmarks Act) that required "all earmarks... to be disclosed 72 hours before they could be considered by the full Senate." That said, Obama is playing politics, too. After long refusing to release his 2005 and 2006 earmark requests--few politician want their records scoured for ties to donors and political allies--the senator suddenly let them fly today. The reason: to challenge Clinton's transparency. (Team Obama has been pressuring Clinton to release her tax returns and White House papers, too.) When asked "why now?" by Lynn Sweet of the Chicago Sun-Times, spokesman Bill Burton said, "Sen. Obama thought it was appropriate to release them." Two hours later, though, communications director Robert Gibbs told reporters that, "if Senator Clinton will not agree to join Senator Obama in releasing her earmark requests, voters should ask why she doesn't believe they have the right to know how she wants to spend their tax dollars." No doubt that Obama did the right thing. But in this case, appropriate = politically expedient.

Where does Clinton stand? Somewhere else, I suppose. For one thing, she's a far more enthusiastic--and effective--earmarker than Obama. Last year, her $342 million tab for New York was the 10th highest in the Senate, according to the budget watchdog group Taxpayers for Common Sense; Obama snagged $98 million. Spokesman Philippe Reines says Clinton is "proud of the investments in New York she has secured," but believes the one-year ban "will allow a hard look at how more sunlight and transparency can be brought to this process." The only problem? That year apparently starts later rather than sooner. At press time, Team Clinton has yet to release any of her earmark requests, deferring press inquiries to her less-than-responsive Senate office.

With McCain and Obama waiting, that's just bad politics.

UPDATE, March 14: And then there's the downside. From the Washington Times:

Mr. Obama and Sens. John McCain and Hillary Rodham Clinton jetted back to Washington yesterday to vote during the annual budget free-for-all that compresses votes on a host of contentious issues into a single day. That meant taking positions on border security, energy independence, President Bush's tax cuts and Democrats' spending plans, each of which might come back to haunt the three major-party candidates still vying for the chief executive's slot, and could be used in this year's Senate elections as well.

No wonder they're more interested in extracurricular activities.