WATERLOO, IOWA, DEC. 17 -- The barely restrained anger of Gary Hart's rivals for the Democratic presidential nomination spilled across the political landscape today with charges that he is untrustworthy, a proponent of "glib phrases" who accomplished little in the Senate, that ambition was the sole reason for his reentering the race and that he is trying "to rewrite the history of this campaign."

Led by former Arizona governor Bruce Babbitt, the angry Democratic candidates have begun to line up to attack Hart for returning from what one today called "his sabbatical from the campaign."

Sen. Paul Simon (D-Ill.) today said here "I'm afraid he {Hart} may have hurt himself" and the Democratic Party. Later, in a statement issued from Washington, he accused Hart of engaging in "an intellectual exercise involving a set of abstract proposals. . . talk in glib phrases about shiny new ideas."

In Chicago, Babbitt went further. "Mr. Hart is going around saying he feels bound to run because nobody else is addressing the vital issues of the day. I resent that. It seems to me that Gary Hart has a hell of a long way to go before he has anything to teach this candidate about grappling with hard choices and standing up for the truth." Later, Babbitt added, "I think anyone is entitled to make a comeback. I don't know if the appropriate model is Sugar Ray Leonard or Jim and Tammy Bakker. . . . "

Rep. Richard A. Gephardt (D-Mo.) issued an indignant statement from San Jose, Calif., in which he charged that former senator Hart is ineffective and untrustworthy. "Frankly, I wonder why Gary has never accomplished many of the things he always talks about. . . . We agree on many things, but unlike Gary Hart, I have the trust of my colleagues."

Democratic National Chairman Paul G. Kirk Jr., who said he was "not elated" by Hart's reentry, took the long view: "As my football coach used to say, 'After you take a hit, take it and go.' "

Said one adviser to a Democratic candidate, "The reality is there are six guys who are furious with Hart. You can't expect them to keep their gloves off long."

Although Democratic leaders are fearful of the effect of Hart's reentry nationwide, the situation here in Iowa is especially acute. In the view of campaign strategists, Hart's move dramatically heightened the significance of the Iowa caucuses.

The theory is that the New Hampshire primary, to be held eight days after the Iowa caucuses, will be viewed as a contest among Hart, Massachusetts Gov. Michael S. Dukakis and whoever wins in Iowa. "The media can only cover so many stories. There's only so much room on your screen. I think three {candidates} is that limit," said one campaign strategist.

Dukakis, who has long led in New Hampshire polls, is assumed to be one of the three. Hart, because of the years he has spent campaigning there and indications that he intends to focus more on the Granite State than Iowa, is assumed to be another.

So the pressure is now on the other candidates to win in Iowa, not just finish "well."

Presidential hopefuls do not have to file here as in New Hampshire, so Hart is a candidate because he says he is one. He will probably join in the first major political event of the new year here, the Des Moines Register debate Jan. 15.

"I assume Hart will play in Iowa, but I can't imagine he'll do very well on caucus night," said Joe Trippi, Gephardt's deputy campaign manager. "The constituency he gathered around his candidacy has been pretty well been divided up. I think the process is too far along there for him to change the dynamics."

"All eyes will be on Iowa," said Simon pollster Paul Maslin. "We've got a dragon out there. The question is who is going to be St. George, who is going to slay the dragon, and the first chance is in Iowa."

Simon may be best positioned for that role. Before Hart's announcement Tuesday, the Illinois Democrat was the front-runner in the state. New polls indicate that Hart's reentry may have damaged all the candidates, except Gephardt, in Iowa.

"The challenge is that the race has a new controversial phenomenon that has the potential to overshadow the whole field," said Chris Hammel, Babbitt's Iowa coordinator. "The challenge is how to communicate through the clutter. We've decided to take our message directly to Gary Hart."

Hammel and others have declared open season on Hart. "The race will get lively. We all now have a target. Not until he {Hart} gets firmly discredited will we be rid of this guy."

Simon, Dukakis and Babbitt campaigned tonight in Iowa. Gephardt is scheduled be here over the weekend. Each seemed to take a slightly different tack in remarks about Hart. Gephardt and Babbitt were especially upset with Hart's charges that, without him, the Democratic field lacked ideas. "Nobody doubts that Gary Hart has ideas, but even Gary can't believe that he has a monopoly on good ideas or that he's the only candidate with a substantive agenda for America's future," Gephardt said.

Simon claimed Hart is unelectable. Dukakis complained Hart's attacks on coverage of his relationship with Miami model Donna Rice are off base. "The issue in the campaign isn't the media coverage of personal lives. The issue is the American future," he said.