Good Thursday morning. It's good to be back in Washington, even as presidential campaigns fan out to the four corners of the country. Here's what's got our interest today:

-- Mitt Romney will make his stand, AP reports, in his home state of Michigan. The former governor has pulled all his advertising from South Carolina and Florida in order to flood the market in Michigan, where he and John McCain are locked in a tight battle. Both candidates held rallies there yesterday before heading to South Carolina for tonight's debate. Both candidates have something of a home-field advantage: Romney was born and raised in Michigan, while McCain won the state in 2000. Now, it looks like the once-front-running Romney is going to lay it all on the line in the Wolverine State. It doesn't help his case that most Democrats are not running on their side, giving independents a big reason to cross over and vote McCain. Come back to RCP tomorrow to read more on that.

-- Romney isn't completely toast yet, and he still has some powerful and deep-pocketed friends. Yesterday, after a disappointing finish in New Hampshire, the camp still managed to raise about $5 million in their second annual National Call Day. Most of that amount, though, is off limits for now: Just $1.5 million of that is available for the primary, the Salt Lake Tribune reports. The event last year, which formally kicked off Romney's fundraising efforts, pulled in an impressive $6.5 million. Even after two disappointing finishes, this year's showing is impressive for a one-day haul.

-- One candidate is complete toast: Bill Richardson has decided to back out of the race, the New York Times and AP report. Richardson made the decision after meeting yesterday with top advisers in New Mexico and is set to make an announcement at a press conference today. Two fourth-place finishes, in which he earned less than 5% of the vote, chased him from the race before he even got to Nevada, where he had put plenty of resources and hoped to compete strongly.

-- Is John Edwards far behind Richardson on his way out the door? After a narrow second-place victory over Hillary Clinton in Iowa and a distant third place finish in New Hampshire, how long can John Edwards continue his bid? Edwards headed to South Carolina yesterday to begin what he was pitching as a homecoming tour, though campaign manager David Bonior was on a mid-day flight back to Washington out of Manchester.

-- Edwards has tweaked his stump speech a little, NBC's Tricia Miller writes, in that he emphasizes his Southern roots. "We have to make certain that every primary voter in South Carolina knows that I was born here," he told supporters in Clemson. Edwards is currently unning another distant third in the latest RCP South Carolina Average at 15%, well below leader Obama's 44% and Clinton's 31%. If Edwards can't win in his home state, will he ever win?

-- And what about Rudy Giuliani? Hizzoner will stay in the race through Florida, and from there it's only a week away from February 5, but without a win there will he choose not to continue? As other candidates start receiving a bounce from wins in other states, Giuliani's slim 5 point lead in the latest RCP Florida Average could slip. But don't question his commitment: Giuliani will spend next Tuesday in Florida as Michigan holds their state's primary, the St. Pete Times reports, meaning New Hampshire is the only state in which he's stuck around to find out what happened.

-- Hillary Clinton's big win in New Hampshire remains something of a mystery: How'd she pull it off? Some answers are filtering out. She won with huge margins in the Southern part of the state, per this map, which sure has a lot more purple (Obama) than green (Clinton). But remember that 80% of the state's population lives in the Southern part of the state, and that region is where Clinton chalked up big margins. Then again, maybe voters -- especially female voters -- did not like the idea of the first female candidate's campaign collapsing, the New York Times writes. Did Obama err when he told Clinton she was "likable enough" at the debate on Saturday? Many women, Politics Nation's mother included, thought so.

-- In Washington yesterday, what may be a battle crucial to both parties' hopes in 2008 came to the Supreme Court as lawyers for both sides argued over a new Indiana law requiring voters to present identifications before casting a ballot. A majority of justices appeared not to accept plaintiff's arguments, the New York Times writes, while they may even go farther and determine that the suit itself was brought in an improper manner, making it that much more difficult to challenge any future statutes that come up. If the court upholds the law, as looks likely, several other states could follow close behind and pass their own voter ID laws.

-- The case has attracted briefs from the Bush Administration, the Republican National Committee, the ACLU, Democratic Secretaries of State from Missouri, Ohio and Vermont and Republican Attorneys General from Texas, Alabama, Colorado, Florida, Hawaii, Michigan, Nebraska and South Dakota, Stateline reports. The case is drumming up some serious partisan rancor, and could have effects far beyond Indiana: Georgia and Florida have similar laws, potentially giving Republicans a leg up come November in those states.

-- Running Mate Of The Day: "You promised me that you would be my running mate," Mike Huckabee told Stephen Colbert on Colbert's show last night. The interview, found here, showed off Huckabee's deadpan humor: He said he would "charge hell with a waterpistol, if necessary," to get Osama bin Laden, and that he still thinks evolution is a farce. Asked by Colbert whether he's the candidate who thinks Jesus and the Devil are brothers, Huckabee had fun with the Romney shot: "No, that's, that's not us. But I'll send you a memo on that and I'll underline all the parts in red that we need to believe," he said. "Stay Huckabee, not a Huckawas," Colbert implored his future running mate.

-- Today On The Trail: Clinton hits Las Vegas for a rally, Edwards volunteers at a food bank in the Lowcountry before rallying the troops in Charleston, and Obama holds a big event there too, before going home to Chicago. Republicans debate tonight in Myrtle Beach, and on the way there, Romney stops in Greenville and McCain has a press conference in West Columbia, a town hall meeting in Greenville and a party with supporter before the debate in Greenville. Giuliani meets supporters at a cafe, Huckabee fundraises and hits a Fair Tax fundraiser in Myrtle Beach, and Ron Paul visits local businesses in Myrtle Beach.