The race for attorney general also could leave Mr. Cuomo smarting.
However, as outrage built over Cuomo's watery denial - his campaign pinned responsibility for the mailer on an anonymous "constituency outreach" volunteer - it emerged on Wednesday that the mailer was drafted by Cuomo's former special assistant David Lobl, now volunteering with his re-election campaign, and approved by Larry Schwartz, the governor's former secretary.
Nevertheless, as the shock primary victory of democratic socialist Alexandria Ocasio-Cortez over Joe Crowley in June proved, fortunes can change in a NY minute.
A landslide victory for Carter in the IL primary that year made some voters think Kennedy's campaign was done, so they began to think of the NY primary as a referendum on the president, The Washington Post reported at the time.
Cuomo also claimed to have no knowledge of the Democratic Party mailer that questioned Nixon's support for Jewish people - despite Cuomo's control of the party and a recent $2.5 million contribution to its campaign operations. His running mate, Lt. Gov. Kathy Hochul, is facing a serious primary challenge from progressive New York City Councilman Jumaane Williams.
"Do gay people turn out to elect the first gay attorney general, or do African Americans turn out to elect the first African American woman attorney general, or do they turnout for Zephyr Teachout?" Meanwhile, corruption in Albany and voters' frustration with it have not subsided. Leecia Eve, a former Cuomo aide, was in fourth.
In the state Senate, several progressive challengers are looking to knock off incumbent Democrats who used to caucus independently from mainline Democrats, allowing Republicans to have the majority in the chamber for the past decade.
The stakes are high for Mr. Cuomo even if he wins, according to Jeanne Zaino, professor of political science at Iona College in NY. For example, if a person wanted to register with a party or switch parties to be able to vote in Thursday's primaries, they needed to register by October 13, 2017, nearly a full year before the actual election.
NY current labor laws make it illegal for public union employees to go on strike, resulting in fines and penalties.
In New York, the subways are theoretically controlled by the governor, who oversees the MTA. He had to fill out an affidavit ballot.
Mayor Bill de Blasio cast his ballot in Brooklyn, though he has not endorsed either candidate.
Polls opened at 6 a.m.in New York City and surrounding counties, and opened at 12 p.m.in 49 upstate counties.
Polls show that race very close going into election day.