Vito J. Lopez, a former community organizer and New York assemblyman who parlayed a small antipoverty center in Brooklyn into a political machine that made him a power broker in New York City and Albany until he was brought down by a sexual harassment scandal, died on Monday in Manhattan. He was 74.

The cause was cancer, his lawyer, Gerald B. Lefcourt, said. Mr. Lopez learned he had leukemia in 1993 and had a recurrence in 2010.

In his heyday, Mr. Lopez, an emotional, sometimes bullying figure, exerted such political power — he was also the Democratic Party leader in Brooklyn — that he was courted by presidential candidates, governors and mayors, Republicans as well as Democrats.

Gripping the wheels of government and politics, he brought hundreds of jobs, thousands of rent-subsidized apartments and an array of social services to one of the borough’s poorest areas. And for 30 years, his constituents rewarded him with their votes.