Charles T. Manatt, chairman of the Democratic National Committee, yesterday criticized the "straw polls" that several state parties and political groups have staged in an attempt to gauge the relative strength of the six Democratic presidential contenders.

"I think they are bogus, they are a waste of time, they drain our candidates' time and attention," Manatt complained to reporters at breakfast. "They are unrepresentative."

But Manatt said he did not think the presidential campaign's quick start would "grind down the candidates too much" nor "bore the voters too much."

"The average voter isn't listening to any large degree at this point. I often think it's after the World Series of the year of the election when they really focus on it in great detail."

A Milwaukee Sentinel poll taken a week after the Wisconsin straw poll in which Sen. Alan Cranston (D-Calif.) upset former vice president Walter F. Mondale tends to bear Manatt out.

Cranston finished third in the survey of 967 voters who said they planned to vote in the primary. The candidates' percentages in the Sentinel poll followed by their percentages in the straw poll: Mondale, 49 and 36; Sen. John Glenn (D-Ohio), 20 and 2; Cranston, 9 and 39; Sen. Gary Hart (D-Colo.), 6 and 22.