AP Photo/Charlie Riedel
Republican presidential candidate, former Pennsylvania Sen. Rick Santorum, addresses supporters at his Iowa caucus party Tuesday, Jan. 3, 2012, in Johnston, Iowa.
AP Photo/Charlie Neibergall
Republican presidential candidate, former Massachusetts Gov. Mitt Romney, and his wife Ann, arrive for a Romney for President Iowa Caucus night rally in Des Moines.
The Des Moines Register,AP Photo/Justin Hayworth
Rep. Michele Bachmann, R-Minn., addresses her supporters at her caucus party at the Marriott in West Des Moines after finishing sixth in the Iowa Caucuses Tuesday night Jan. 3, 2012.
AP Photo/Evan Vucci
Republican presidential candidate, Texas Gov. Rick Perry, pauses on caucus night Tuesday in West Des Moines, Iowa. Perry announced in his remarks that he would return to Texas to "reassess" his campaign and determine whether there is a "path forward" for him in the 2012 race.
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Rep. Ron Paul and his wife Carol Paul greet supporters during a rally on the night of the Iowa caucus at the Courtyard Des Moines Ankeny on January 3, 2012 in Ankeny, Iowa. Paul came in third in the Iowa GOP caucuses.
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Voters register at the Ankeny 9 Republican caucus on January 3, 2012 in Ankeny, Iowa. Iowans were preparing to caucus to vote for their favorite Republican candidate for president.
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A boys sits behind a desk for electoral official to register voters during Republican caucuses at a school in Des Moines, Iowa, on January 3, 2012.
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An elderly couple register to vote during Republican caucuses at a school in Des Moines, Iowa, on January 3, 2012.
AP Photo/Charlie Riedel
A worker walks past bags of balloons as a hotel ballroom is prepared for an Iowa republican presidential caucus victory party for Santorum.
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Voters register to cast their ballots during republican caucuses at a school in Des Moines, Iowa, on January 3, 2012.
AP Photo/Charles Dharapak
Technician Richie Beanan irons the American flag as he prepares the stage for the caucus night rally for Republican presidential candidate, former Massachusetts Gov. Mitt Romney, in Des Moines, Iowa, Tuesday, Jan. 3, 2012.
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Electoral officials get ready for voters before the start of voting at republican caucuses at a school in Des Moines, Iowa, on January 3, 2012.
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Voters register to cast their ballots during Republican caucuses at a school in Des Moines, Iowa, on January 3, 2012.
AP Photo/Dave Weaver
Voters debate during a caucus of precinct 42 near Smithland, Iowa, Tuesday, Jan. 3, 2012.
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A voter writes his vote on a ballot during republican caucuses at a school in Des Moines, Iowa, on January 3, 2012.
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Voters write their candidates' names on ballots during Republican caucuses at a school in Des Moines, Iowa, on January 3, 2012.
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Electoral officials count ballots during Republican caucuses in Des Moines, Iowa, on January 3, 2012.
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Votes are counted in the Third Ward Precinct 1 caucus Tuesday night, Jan. 3, 2012, in the library of Mason City High School in Mason City, Iowa.
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Republican presidential candidate, Texas Gov. Rick Perry poses for a portrait with supporters while waiting to hear the results of the caucus at the Sheraton January 3, 2012 in West Des Moines, Iowa.
AP Photo/Charlie Riedel
Republican presidential candidate former Pennsylvania Sen. Rick Santorum, second from right, looks over Iowa Republican presidential caucus returns with campaign staff in his hotel room Tuesday, Jan. 3, 2012, in Johnston, Iowa.
AP Photo/Charles Dharapak
Kevin Knudson of Omaha, Neb., a supporter of Republican presidential candidate former Massachusetts Gov. Mitt Romney, cheers early returns at the caucus night rally in Des Moines, Iowa, Tuesday, Jan. 3, 2012.
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Members of the Duggar family, prominent supporters of Republican presidential hopeful and former U.S. Sen. Rick Santorum, watch live news reports showing Santorum in the lead at the Stoney Creek Inn on January 3, 2012 in Johnston, Iowa.
Cliff Jette,AP Photo/The Gazette
Observers for the candidates and spectators gather to watch volunteers count the ballots for the Republican presidential nominee during a caucus in the cafeteria at Kennedy High School in Cedar Rapids, Iowa on Tuesday, Jan. 3, 2012.
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Paul and his wife Carol Paul look on during a rally on the night of the Iowa caucus at the Courtyard Des Moines Ankeny on January 3, 2012 in Ankeny, Iowa.
AP Photo/Chris Carlson
Republican presidential candidate former House Speaker Newt Gingrich speaks during his caucus night rally in Des Moines, Iowa, Tuesday, Jan. 3, 2012.