 Due to Lugar's unpopularity among some Tea Party voters on his positions regarding illegal immigration, voting to confirm then-U.S. Supreme Court nominees Sonia Sotomayor and Elena Kagan, the DREAM Act, the START Treaty, some gun control bills, and congressional earmarks, he was challenged by a Tea Party-backed candidate.The Indiana Debate Commission's GOP primary debate with Sen. Richard Lugar and State Treasurer Richard Mourdock was set to air at 7 p.m. EDT on Wednesday, April 11.In a widely published poll taken March 26 to 28, Lugar was still in the lead, but by the time of a second published poll from April 30 to May 1, Mourdock was leading 48% to 38% for Lugar.