Guys like Ed Koch fed off that environment, sneeringly referring to the Central Park Five as "alleged" perpetrators, "even though we all know they're guilty." (They weren't.) Morton Downey Jr. went farther -- Èvocateur has footage of Koch saying he wouldn't go on Downey's show because "it looks like a lynch mob" -- but not as much as you might think. When I first saw Downey it was a death penalty episode, which he introduced by saying, "What we should we do with criminals? HANG 'EM!" Since Koch won the mayorship with an ad that said "I'm for the death penalty. Are you?" I don't see a huge difference.
Pat Buchannan was interviewed for Èvocateur and said Downey was a precursor to Hannity and Glenn Beck. This may have been true on some levels, but the audiences were very, very different. The Morton Downey Jr. Show was filmed in New Jersey, and audiences looked like Jersey Shore rejects and Sopranos extras. It had little presence in the South -- Kimberly, who grew up in Georgia, had never heard of the man -- which may have shared the politics, but would've hated the bile, the screaming and the calculated rudeness. They would've rejected Downey, just as they rejected Giuliani twenty-years later (and will probably reject Chris Christie next cycle).
No, when crime declined in the 1990s and Bill Clinton brought Democrats back to the White House, the audience for that sort of thing disappeared. Clinton moved right on crime and welfare, leaving the GOP to oppose him on issues like gun control and gay rights, taking positions Jersey or Long Island suburbanites didn't care about or found actively repellent. (That episode of Hill Street Blues had the cops coercing confessions from a pair of black men, with the show's approval; but it also featured a sympathetic, if embarrassingly cliched, portrayal of a gay prostitute.) The cult of Reagan was taken up by Southerners, and the Republicans became a strictly regional party. Altogether it's a change for the better.