Here are today's top election stories, beginning with a major endorsement for Rudy Giuliani:

"In a Surprise, Pat Robertson Backs Giuliani" (David Kirkpatrick and Michael Cooper, New York Times) Pat Robertson's endorsement yesterday of Giuliani is somewhat tempered by the fact that the two are friends, but it's still a positive sign for Rudy's campaign, which needs evangelical support to win the nomination.

"Poll Suggests Clinton Is Vulnerable" (John Harwood, Wall Street Journal) Hillary Clinton still leads by a wide margin in the latest NBC/WSJ poll, although a plurality (46%) rate her negatively on the issue of honesty. Perhaps more significant, in a head-to-head matchup, Clinton and Giuliani are virtually tied. On the GOP side, the big news is the tumble for Fred Thompson, who dropped 8 points since September.

"Clinton Down Following Debate, Polls Find" (David Paul Kuhn, The Politico) Following a debate which Clinton described as not her best, the frontrunner has taken a hit in some recent state polls.

"Consensus Lacking in GOP Endorsements" (Michael Shear and Alec MacGillis, Washington Post) Although Rudy scooped up Robertson's endorsement, John McCain picked up Sam Brownback's and Mitt Romney got Paul Weyrich's, underscoring the fact that the Christian Right is far from unified behind a single candidate. The lack of consensus probably helps Giuliani the most, since social conservatives appear too divided to unite against him.

"Bloomberg's White House Answers Evolve" (Sara Kugler, Associated Press) What does it mean that Michael Bloomberg has gone from saying "I'm not running" to "I'm not a candidate"? Beats us, but it could be significant, and, in any case, it's always fun to speculate.

"Obama Confronts Generational Rifts" (Brian DeBose, Washington Times) An interesting new line of attack for Barack Obama is to go after Hillary's age, or, rather, her belonging to the '60s generation, whose members have been fighting the "same fights" for decades. Now, Obama, you know you're not supposed to talk about a woman's age, don't you?

"Ads, Networking Pay Off For Romney in S.C." (Aaron Gould Sheinin, The State) It wasn't so long ago that Romney was struggling in South Carolina. Things are now looking up, which just goes to show what a little bit (or a lot) of spending can do.

"McCain Shifts on Immigration" (Daniel Gonzalez and Dan Nowicki, Arizona Republic) It was probably inevitable that McCain would eventually have to adjust his immigration views. The question is whether conservatives are ready to forgive him.

"Edwards Advocates Combat 'Expeditions' " (Jenn Abelson, Boston Globe) In trying to highlight whatever daylight exists between the leading Democratic candidates' Iraq plans, John Edwards says that he would not keep troops in the country to fight al Qaeda, as Clinton would. Instead, says Edwards, he would continue to pursue al Qaeda from bases outside the country.

"It's the Misquoting, Stupid" (Abdon Pallasch, Chicago Sun-Times) While in Chicago, Bill Clinton disputed reports that he has criticized his wife's rivals. "I've got a hard and fast rule here: I don't criticize the other Democrats." Call it Clinton's 11th Commandment.

Get these and today's other election stories at RCP's Politics and Election Page.