Landon Peterson peeks out of the voting booth while his mother Meghan votes March 20, 2012 at Christian union Church in Metamora, Illinois. White House hopeful Mitt Romney eyed a big win in President Barack Obama's home state Tuesday as he sought to clinch the Republican nomination and focus on November's general election. Polls across Illinois opened for the state primary at 6:00 am (1100 GMT) with former Massachusetts governor Romney the odds-on favorite to win. TOPSHOTS AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)