The Mourdock campaign inserted a picture of the embattled candidate with Daniels into its ad featuring GOP presidential candidate Mitt Romney. The new spot began airing Friday.
Daniels ducked a question about Mourdock's comments on Comedy Central's "The Colbert Report" Thursday night, telling Stephen Colbert he's a "non-combatant" in the race. Daniels has declined to campaign for candidates since being picked as Purdue University's next president, but still occasionally gives political analysis.
Mourdock has refused to apologize for the comment, saying he was misunderstood and never meant that God intends rape. His campaign has called reaction from Democrats "sleazy."