Even without the heartbreak of loss, this was bound to be a crossroads moment for a vice president who has spent four decades in Washington only to find an uncertain path ahead. He has not ruled out running for president again, and some friends are nudging him to, even if the political math does not seem to favor it. But he has good days and bad days, his mind never far from his late son, Beau Biden, and his staff is not planning further than two weeks ahead.

“This is not a guy who is going to go easily,” said former Senator Ted Kaufman, a longtime confidant appointed to fill Mr. Biden’s seat representing Delaware in the Senate after the 2008 election elevated him to the vice presidency. “Whatever he’s doing, he’s going to stay involved. He’s not looking to retire, like me. He’s pretty clearly in the ‘I’m going to do everything I can to use what I’ve learned to be involved.’ ”

Whether that means another campaign remains unclear. Mr. Biden, 72, has 18 months left in his current job, and advisers said he felt a duty to its responsibilities. It has also been therapeutic to get back to the White House and focus on issues like clean energy and foreign policy. Among his assignments are the dicey challenges of Ukraine and Iraq. And just over the horizon is another potential budget battle.

Read the article “Is Biden Planning a Presidential Run?” on nytimes.com.