McKane became a Democratic Party ward boss and had loose standards on who was allowed to vote: immigrants, dead people, seasonal migrant workers, and criminals. Voting records show many specious entries. On the eve of the 1893 election, William Gaynor, a lawyer running for Brooklyn Supreme Court Justice, decided to test McKane's methods by dispatching more than 20 Republican observers to examine the Gravesend voter registries and oversee the voting in all six districts of the town, as he was entitled to do by law. However, when the observers reached Gravesend town hall at dawn on election day, McKane, along with a large group of policemen and cronies, confronted them. When the observers balked and produced injunctions from the Brooklyn Supreme Court, McKane supposedly declared "injunctions don't go here" and ordered the men away. A scuffle ensued and five of the observers were beaten and arrested. This event raised great outrage. Early in the following year, McKane was tried, convicted, and sentenced to six years in Sing Sing for such corruption. He was released near the end of the century and died of a stroke in his Sheepshead Bay home in 1899.