Obama’s pledge to not endorse a candidate in the primary could be complicated by whether his former vice president, Joe Biden, decides to join the race. Biden and Obama have not had a detailed conversation about his plans, two people familiar with the matter say, but are expected to speak about it before Biden makes a decision in the coming weeks.

Axelrod, who also served in the White House for the first two years of the Obama administration, described their relationship as “exceptionally close.”

“Whether that would encourage President Obama to intervene in the race, I don’t know. I doubt it,” Axelrod said. “I think he’s going to allow the candidates to make their own case. He believes in the process and believes the best candidate will emerge from that process.”