Sullivan began his career as a political operative in 2000, and ran his first New York race in 2008, the same year he helped Gillibrand win re-election to the House. He was fresh off a stint with the Democratic Congressional Campaign Committee in early 2011 when Ms. Hochul, then the Erie County clerk, decided to run in a special House election in western New York. She hired Mr. Sullivan as campaign manager because of his experience running special elections and his conviction, shared by few, that she could win. Despite long odds, she did. Hochul’s campaign reported paying $50,000 since 2021 to a limited liability company that Mr. Sullivan controls, “ACS Campaign Consulting.” But The NYTimes found that he had earned $500,000 or more in a secretive arrangement where he received a portion of what the campaign spent on TV ads. He managed a Senate race in New Mexico in 2012 and was Senator Mary Landrieu’s campaign manager in her failed re-election bid in Louisiana in 2014, until he was abruptly fired just weeks before Election Day. Governor Hochul appears to have been his only major political client since 2015.