The 1984 Iowa presidential caucuses aren't next week, they just seem like it to all those eager Democrats.

Reubin Askew, the former Florida governor, has already been to the Corn State twice. "A low-key testing of the waters," one associate says. So low-key hardly anyone noticed he'd passed through.

Sen. Gary Hart (Colo.), saying he "probably will run" in 1984, attended a pork chop and pie fund-raiser in Indianola for Rep. Tom Harkin and a United Auto Workers union gathering in Waterloo.

Former vice president Walter F. Mondale went him one better. In just one day last month, he attended all six Democratic congressional district conventions and held a press conference.

The latest candidate to pass through is Sen. Ernest Hollings (S.C.). He said, to no one's surprise, that he is thinking about the presidency. So is Sen. John Glenn (Ohio), who is scheduled to give the keynote speech at the state party convention June 18. Senate Minority Whip Alan Cranston (Calif.), who made his first Iowa visit in February, says he'd like to come too.

All this is just fine with state Democratic chairman David Nagel. The presidential hopefuls, he says, help build party unity. They also help Iowa Democrats raise money.