Democratic presidential hopeful Sen. Hillary Rodham Clinton, D-N.Y. acknowledges supporters during a primary night rally Tuesday March 4, 2008, in Columbus, Ohio. Clinton won the Ohio, Rhode Island and Texas primaries to stay in the race for the Democratic nomination. Standing with Clinton are Rep. Stephanie Tubbs Jones, D-Ohio, and Ohio Gov. Ted Strickland.
Republican presidential hopeful, Sen. John McCain, R-Ariz., and his wife Cindy McCain react to the crowd at his primary election watch party in Dallas, Tuesday, March 4, 2008. McCain surpassed the requisite 1,191 GOP delegates to clinch the Republican presidential nomination.
Democratic presidential hopeful Sen. Barack Obama, D-Ill., and his wife Michelle wave as they leave the stage during an election rally Tuesday, March 4, 2008, in San Antonio, Texas. Obama won the Vermont primary for his 12th straight victory in one month's time, but then the night turned as rival Hillary Rodham Clinton won in Ohio, Rhode Island and Texas.
A voter enters the polling station at the Alcazar Hotel in Cleveland Heights, Ohio to vote in Ohio's primary election on Tuesday, March 4, 2008. Barack Obama sought a knockout against rival Hillary Rodham Clinton as voting began Tuesday in crucial contests in Texas and Ohio, where the former first lady desperately needed a win to salvage her once-powerful candidacy for the Democratic presidential nomination.
A voter arrives to cast her vote in the Texas primary election at a polling location in Dallas, Tuesday, March 4, 2008. Voters go to the polls in Ohio, Rhode Island and Vermont as well.
Voters leave the polling area after casting their votes in the Texas primary in Keller, Texas, Tuesday, March 4, 2008.
A poster hangs from a table as a voter completes her ballot at Joy Park Community Center in Akron, Ohio on Tuesday, March 4, 2008.
Voters are checked before casting their ballot at Nativity School in the Pleasant Ridge section of Cincinnati early Tuesday March 4, 2008.
A line of voters cast their ballot in the primary election Tuesday, March 4, 2008, in Columbus, Ohio.
Karen Tucker votes while holding son Jack so he can watch Tuesday, March 4, 2008, at the Mack Volunteer Fire Department Fire House in Green Township, Ohio. Her son Matthew, 4, stands on tiptoe to get a better view.
Voting booths are full at the White Oak Christian Church in Colerain Township, Ohio, Tuesday March 4, 2008.
A voter casts her ballot in the primary election, Tuesday, March 4, 2008 in Columbus, Ohio.
Simone, left, and Vivian Punchak, twin 9-month-old girls, wait as their mother Amy Punchak votes in the presidential primary in Providence, R.I., Tuesday, March 4, 2008.
Phineas Gadd, 3, holds his father's leg as Dan Gadd votes in the primary election in Plainfield, Vt., Tuesday, March 4, 2008.
Selectman Keith Terry fills out some paperwork at the polling place in Plainfield, Vt., Tuesday, March 4, 2008. With their presidential primary election suddenly relevant, Vermont voters are heading to the polls on a day when election officials expect heavy turnout.
Voters cast their primary election ballots at the Van Wert County Fairgrounds, Tuesday, March 4, 2008, in Van Wert, Ohio. The only voting site in Van Wert, combines 18 precincts voting at 40 booths.
Gordon Hamm, left, and his wife Jimmie Hamm leave the polling area after voting in the Texas primary in Justin, Texas, Tuesday, March 4, 2008.
Arya Kamangar from Merced, Calif., stands in the rain Tuesday, March 4, 2008, near a voting precinct in Columbus, Ohio. Heavy rain fell in much of the state Tuesday morning with a forecast of freezing rain, sleet and maybe snow by the time voting wrapped up. Ohio's presidential primary typically comes well after a nominee is decided. But the Clinton-Obama race has remained tight, making Ohio's contest key.
Joe Higgins, of Middleburg Heights, Ohio, urges motorists to honk for their favorite Democratic presidential candidate Tuesday, March 4, 2008, as he calls in results of the "Wilde and Fee's Big Honkin' Exit Poll" in Lakewood, Ohio. Wilde and Fee are drive-time radio deejays in Cleveland.
An icicle hangs from a flag in front of Echo Hills Elementary School which is one of many places for voters to cast their ballots Tuesday, March 4, 2008, in Stow, Ohio.