In the Land of George Santos, Machine Politics Fuels a G.O.P. Revival

It was the biggest event of Mazi Pilip’s campaign in a must-win special House election in New York. The No. 3 House Republican had flown in. A half-dozen congressmen led a crowd in chants of “Mazi! Mazi!”

There was just one thing missing from the Republican show of force at a Veterans of Foreign Wars hall the other day: the candidate, who was home observing Shabbat.

In any other race, her absence would have been a deal breaker. But on Long Island, the event vividly illustrated an open secret animating Tuesday’s contest to replace former Representative George Santos. Ms. Pilip’s name may be on the ballot, but the campaign belongs to the Nassau County Republican machine.

After decades of electoral losses and corruption scandals, the organization has roared back to life in the New York City suburbs, reviving a political tradition that has largely become an anachronism elsewhere in the country.

In just the last three years, Republicans have swept every major office in the county, filling high-profile posts and hundreds of patronage jobs with party regulars often obliged to return the favor come campaign season.

Joseph G. Cairo Jr., the group’s silver-haired chairman and de facto boss, handpicked Ms. Pilip, 44, a part-time county legislator, and is now serving as her chief strategist, fund-raiser and surrogate. He has dispatched loyal lieutenants to be her spokesmen and campaign handlers. And in previously unreported conversations, he browbeat party leaders in Washington to spend more on advertising.