A high-ranking Democratic New York State senator was arrested on Tuesday and charged with trying to buy a place on the Republican ticket in the city's next mayoral race, an effort that prosecutors said was part of a wide-ranging bribery scandal and reflected pervasive corruption in New York politics. Five other politicians, all Republicans, were also arrested and charged with collectively accepting more than $100,000 in bribes in meetings in parked cars, hotel rooms and state offices, according to court papers.