Obama is particularly enthusiastic, aides said, about taking on Donald Trump. The Republican candidate has personally offended the president with his conduct on the campaign trail — Trump referred to a black supporter on Friday in one of his crowds as "my African-American" — and as the most visible champion of the "birther" conspiracy theories that falsely hold that Obama was born in Kenya rather than Hawaii.
Should Clinton do well enough in the primaries on Tuesday to give her sufficient delegates to claim the Democratic nomination, Obama is likely to move swiftly to make a case for her.
"He has indicated he wants to spend a lot of time on the campaign trail, so when it's time to do that, we'll go out guns ablazing," Jennifer Psaki, Obama's communications director, said in an interview. "We are actively thinking through how to use the president on the campaign trail — what works for the nominee, what works for him, and how to utilize his strengths and his appeal."
Jennifer Palmieri, Clinton’s communications director, said that Clinton hoped to earn Obama’s endorsement and his active participation in the campaign during the summer and fall.