HANOVER, N.H. — Joe Biden’s campaign wanted to make Friday a celebration of the time Barack Obama chose him as his running mate.

But on the stump, the Democratic presidential candidate veered off message and posed an out-of-nowhere hypothetical: What if the first black president had been killed?

"Imagine what would have happened if, God forbid, Barack Obama had been assassinated after becoming the de facto nominee,” Biden said. “What would have happened in America?”

Heading into the speech on Friday, Biden’s campaign was touting the Aug. 23 anniversary of Obama choosing him as his vice presidential running mate in 2008.

Biden’s question, which came at the tail-end of an otherwise normal speech, was aimed at a group of young Democrats from Dartmouth College. A campaign adviser said it was an effort to connect with young people and discuss the turbulence of the times when he was in college.

“I have one hero who was my dad, but I have two political heroes ... Martin Luther King and Bobby Kennedy,” Biden said. “My senior semester, they were both shot and killed."

The question came just days after Biden, known for his verbal flubs and off-message gaffes, mistakenly said the two men had been assassinated in the 1970s instead of 1968.

Biden brought up the question as part of a discussion about what causes young people to become politically involved. He said it was the assassinations, but that young people today are being motivated to vote against President Donald Trump.

“Unless I’m mistaken, Donald Trump did for your generation what the loss of two of my heroes did for mine,” he told the students, adding, “What they did was make you realize: My God, we’re in trouble.”