New York Mayor Edward I. Koch (D), who's not shy about speaking his mind, does not think much of the six announced Democratic presidential candidates. In fact, he doesn't think any of them can beat his favorite announced candidate, Republican Sen. Dole.

Koch, who appears on political talk shows as a "mayor/columnist," said in an interview last week he thinks "that we won't win with one of those six . . . . I don't think they convey the leadership quality that people are looking for. They don't have the magnetism that {New York Gov. Mario M.} Cuomo has, or that {New Jersey Sen. Bill} Bradley has." The Koch scenario is that desperate Democrats will turn to Cuomo or Bradley at next summer's national convention.

Koch, who gave President Jimmy Carter's campaign fits in 1980 when he warmly embraced Republican Ronald Reagan, is again reserving his kindest words for a Republican. "Dole has magnetism," he said. "I think he's the strongest candidate. I think he's going to be the Republican candidate."

The mayor dismissed the GOP front-runner, Vice President Bush, as "sort of a Connecticut preppie." Even some of the current crop of Democratic candidates could defeat Bush, he said.