[QUOTE=OtakuLoki]
For that matter, I’d like to point out that Billdo’s list of prominent NYS politicians has a small flaw - Thomas Dewey, the former governor who ran for President against Truman, may have done so from the position as a former NYS governor, …
[/QUOTE]
You are correct, and Teddy Roosevelt was New York City Police Commissioner in addition to the other positions he held, but none of the prominent Presidents or candidates served as Mayor.
In fact, if Wikipedia is to be believed, none of the Mayors after the 1898 consolidation have gone on to hold any significant office after their Mayoralty. Indeed, as far as I can tell, the only two Mayors who were nationally significant after their terms date back to the era before 1821 when Mayors were appointed by the state government.
Edward Livingston was appointed Mayor from 1801 to 1803, after having served in the House of Representatives. In 1804, Livingston moved to Louisiana, where he served as a Representative and Senator before being appointed U.S. Secretary of State from 1831 to 1833.
DeWitt Clinton, after serving briefly in the U.S. Senate (and resigning because of the living conditions in the then-new Washington, DC), was appointed Mayor three times, 1803 to 1807, 1808 to 1810 and 1811 to 1815, simultaneously serving as Lieutenant Governor from 1811 to 1813. In 1812, he ran for President as a candidate of the Federalists and a break-away segment of the Democrat-Republicans, obtaining 47.6% of the popular vote but losing to James Madison. He was elected Governor of New York in 1817, serving through 1822, and reelected Governor in 1924, serving until his death in 1828.
In other words, you need to go nearly two centuries to DeWitt Clinton to find a New York Mayor who became Governor or a major party Presidential nominee.