SANTA MARIA DI CASTELLABATE, Italy — On a recent afternoon, Alessia D’Alessandro ran into a couple of friends on the boardwalk of the town along the southern Italian coast where she spent her teenage summers swimming in the sea and living with her mother in the local prince’spalace.

“They were like, ‘Oh, my god, you came back!” said the 27-year-old, who had left Italy after high school to pursue academic and employment opportunities in her mother’s native Germany. “What are you doing here?’”

Many Italians are asking the same thing.

Before critical elections on March 4, Italy’s leading party, the anti-establishment Five Star Movement, has sought to counter its image as a eurosceptic movement populated with unqualified, web-based activists by recruiting candidates from the country’s professional class. This month, they reimported Ms. D’Alessandro, a self-described “child of Europe,” from her job at a Berlin think-tank, and prominently rolled her out as a response to patronage politics as usual in the pivotal south.

But revelations that the party’s leadership inflated Ms. D’Alessandro’s résumé — apparently without her knowledge — drew criticism that the party was fundamentally dishonest, unprepared to govern and, most damningly, just like other parties.