Is Joe Biden running for president? Effectively yes, even though he is not yet a declared candidate.

Buzz has grown about a potential Biden candidacy this week after The Times columnist Maureen Dowd wrote that he was considering entering the race, in part because of urging from his son Beau, who died in May.

Media accounts have suggested that the decision will be made during a family vacation in September, but Mr. Biden is functionally already a candidate in the so-called invisible primary, which plays an enormous role in nomination contests. The question now is whether he will receive enough support to decide to make it official.

The case for Mr. Biden is most convincing to Democrats who are worried about Hillary Clinton’s declining favorability numbers in the polls (though both the extent of the decline and its implications for the general election have been greatly overstated). The vice president is seen as less polarizing and not encumbered by scandals and investigations.