But it has been Democratic candidates who have had to address the issue of the mosque.
In Illinois, Rep. Mark Kirk, the Republican running for Obama's former Senate seat, said he respects religious freedom but suggested the Islamic center be built at a "less controversial site."
His challenger, Illinois Treasurer Alexi Giannoulias, defended the decision to build the facility.
"This is about every single religion and remembering what this country was founded on," Giannoulias said as he visited the state fair in Springfield. "You can't just say things when they're nice and flowery. You have to say them when it's the right thing to do."
His remarks came one day after the Senate's top Democrat, Harry Reid of Nevada, came out against plans to build a mosque near the World Trade Center site.