Pro-Palestinian Groups Seek to Block a Vice-Presidential Contender

Gov. Josh Shapiro of Pennsylvania took the stage at Wissahickon High School in the Philadelphia suburbs on Monday to the roars of his fellow Democrats, a campaign appearance and an audition all in one.

As he enthusiastically shouted out his support for Vice President Kamala Harris’s presidential campaign, the pro-Palestinian demonstrators who had dogged Democratic politicians last spring were nowhere in evidence. There was only the adoration of an audience from his native Montgomery County, which the Democratic ticket must carry by sizable margins in November to win Pennsylvania.

But as Ms. Harris prepares to name her running mate ahead of a rally on Tuesday in Philadelphia, those protests are very much part of the calculus surrounding Mr. Shapiro, who is believed to be on her shortlist of potential running mates.

An effort by a motley group of left-wing and pro-Palestinian activists to derail his nomination has presented the Harris campaign with a decision as the vice president prepares to make one of most significant choices of her career: Should she take the opportunity to stand up to her far-left flank in an appeal to the center of the party and to independents, or should she shy away from inflaming an issue that has divided and bedeviled the party — Israel’s war in Gaza?

“Harris needs to win Pennsylvania, signal moderation and reassure Haley voters that she’ll stand up to the left,” said Representative Jake Auchincloss, a Massachusetts Democrat, a Jewish military veteran and an admirer of Mr. Shapiro, referring to Republican supporters of Nikki Haley. “The more the Twitter left piles on him, the more helpful he is to Harris.”

Mr. Shapiro, an observant Jew who speaks openly about his faith, has taken a position on the war that is not all that different from any of the other Democrats under consideration to be the vice president’s running mate, or from Ms. Harris’s.