DES MOINES, Iowa – Four years ago, eighth grade civics teacher Alex Hammer went to caucus for liberal Democratic Rep. Dennis Kucinich of Ohio and voted for President Obama in the general election. But tonight, he walked into the cafeteria of the Oak Park elementary school here and changed his party registration on site to vote for Republican presidential candidate Rep. Ron Paul, R-Tex.

Hammer’s decision was one that was repeated throughout Iowa, putting Paul in a dead heat to win the state’s hotly contested caucuses. According to entrance polls, 25 percent of caucus-goers were Democrats or independents (up from 14 percent four years ago, when there was an active Democratic primary). Of the independents, 44 percent went to Paul, compared to 18 percent for Mitt Romney, who was the next closest.