Who's on first today?

Rep. Ron Paul of Texas is now leading the pack in Iowa as Newt Gingrich's support fades.

Paul now has the vote of 23 percent of 597 likely Republican caucus voters, according to Public Policy Polling, in a survey taken from Dec. 16-18. Mitt Romney is close behind at 20 percent, while Gingrich as slipped dramatically to 14 percent. Fourth place is a dead heat between Rick Santorum, Michele Bachmann, and Rick Perry at 10 percent. While Jon Huntsman is gaining traction in New Hampshire, in Iowa he's only got 4 percent of the likely voters. Gary Johnson comes in at 2 percent.

“Newt Gingrich’s Iowa support was extremely soft and has collapsed in only two weeks,” said Dean Debnam, President of Public Policy Polling. “Ron Paul has taken the lead, but it will be interesting to see if he can turn out his unique base of voters for the caucus. If any of the second-tier candidates see their supporters abandon them in the final two weeks, Mitt Romney is the most likely beneficiary and it could propel him to the win.”

Paul's strongest support is coming from two groups in Iowa, says the poll. Among voters under age 45, Paul gets 33 percent to Romney's 16 percent. The other base of support for Paul is voters who identify as either Democrats or independents. "Young people and non-Republicans are an unusual coalition to hang your hat on in Iowa, and it will be interesting to see if Paul can actually pull it off," notes the Public Policy Polling report.

The polling data shows that Romney's base among seniors is twice as strong as Paul's. Romney gets 31 percent of seniors, while Paul's only getting 15 percent. And among all GOP voters, Romney leads Paul 22 percent to 19 percent.

Over the weekend, the influential Des Moines Register, Iowa's largest newspaper, endorsed Mitt Romney.

"Sobriety, wisdom and judgment.

"Those are qualities Mitt Romney said he looks for in a leader. Those are qualities Romney himself has demonstrated in his career in business, public service and government. Those qualities help the former Massachusetts governor stand out as the most qualified Republican candidate competing in the Iowa caucuses," wrote the Des Moines Register editorial board in their endorsement.