Clinton Opens His Campaign For NAFTA From the Associated Press and Marshall Ingwerson, reporting from Washington.

TRYING to catch up with the critics, President Clinton is soliciting the help of three former presidents to wage a high-profile fall campaign for a free-trade agreement with Canada and Mexico.

He was to sign environmental and labor side deals to the proposed North American Free Trade Agreement Sept. 14 with former Presidents Bush, Carter, and Ford looking on.

``This is one of the most impressive coalitions I've seen,'' Trade Representative Mickey Kantor said Sept. 14 on NBC. In addition, the agreement is backed by former Presidents Reagan and Nixon, top congressional leaders, and all living Nobel Prize-winning economists, he said.

Accused of spending too little time on NAFTA, the president planned to follow up with a visit to New Orleans Sept. 15 to promote the pact. His Cabinet will be dispatched across the country to sing its praises.

As recently as the end of last week, White House press secretary Dee Dee Myers told reporters the president planned no travel this week. She also said that the effort to enlist former presidents in a show of support for NAFTA was abandoned due to scheduling problems. The change in plans became firm, apparently, sometime on Sept. 14.

These statements registered immediately in the political community here as a backpedaling in the president's support for the agreement. NAFTA supporters have been frustrated that the White House has not used its many opportunities to promote it while critics have held a high media profile.

Treasury Secretary Lloyd Bentsen on Sept. 13 rejected suggestions that the administration was holding back its lobbying effort because of strong opposition from labor and environmental groups that had heavily backed Mr. Clinton's presidential campaign. ``We will win it,'' he said. Another HUD trial opens

Deborah Gore Dean, a former aide to one-time Housing and Urban Development Secretary Samuel Pierce, went on trial Sept. 13 in Washington. She is accused of conspiring to award housing projects to favored businessmen, accepting an illegal gratuity, lying to Congress, and other felony counts relating to influence-peddling.

Defense attorney Stephen Wehner told the jury that it was Mr. Pierce who was responsible for all of Ms. Dean's actions. But prosecutors charged that Dean manipulated HUD programs.