BRIDGETON, N.J. — At this stage in her Democratic primary campaign, Tanzie Youngblood has mastered the politician’s art of interrupting strangers in diners to talk about politics. Approaching slowly and clutching a campaign pamphlet with her image, she leaned over and quickly shifted the conversation from what to order to universal health care.

“It affects us all, Republicans and Democrats,” she said to Naomi Ingraldi, 52, as a waiter placed an oversized omelet on the table at the Bridgeton Family Diner.

But then Ms. Youngblood, a retired teacher, ended her pitch with a purposeful line: “I’m not on the traditional line, but I am a Democrat, you just gotta find me,” she said. “Find me on that ballot!”

In the final days before Tuesday’s primary election, this seemingly esoteric request has become essential for Democratic candidates like Ms. Youngblood who did not win the coveted county party endorsements that place their name in the first column on primary ballots.