Attention Nafta Shoppers!

It's hard to imagine that someone as freewheeling as Bill Clinton could become a disciplined guerrilla warrior. Yet the President has deliberately gone underground in his battle for congressional approval of the North American Free Trade Agreement. That pact, which would tear down most trade barriers between the U.S., Mexico and Canada, is faring poorly under the damaging "air war" of television ads, talk-show appearances and telephone banks designed by labor unions and Ross Perot. So Clinton is fighting back in defilade -- in the congressional districts of 100 undecided lawmakers whom he believes can be won over with special attention and favors.

Laura Tyson, the top White House economist, was dispatched to Atlanta last Wednesday to drum up support for NAFTA among two groups of business leaders. Tyson's trip was designed, in part, to put pressure on Democratic Representative Buddy Darden and other members of the Georgia delegation who are still not sure how they will vote.

Transportation Secretary Federico Pena spent Thursday in Baltimore, Maryland, touting the benefits NAFTA would shower on a dredging-equipment firm that exports 80% of its products overseas. Not coincidentally, Pena spoke not far from the home district of Representative Ben Cardin, another Democrat who remains undecided about NAFTA.

Later that day, Treasury chief Lloyd Bentsen told Texas Instruments workers in Representative Sam Johnson's north Dallas district that the firm would add 2,000 jobs if NAFTA is approved. Johnson's vote too is up for grabs.

Such targeted hits have helped Clinton halt the progress of anti-NAFTA forces since September and begin to pick off votes in the House of Representatives, where NAFTA faces a make-or-break vote Nov. 17. But a more important ingredient in this campaign is that Clinton himself has moved to a concerted "inside game" in which he concentrates less on public appearances than on behind-the-scenes lobbying. "We now have the momentum on our side," says Representative Bill Richardson, a key House vote counter. "I would not have said that two weeks ago."

One sign of Clinton's seriousness is that the NAFTA campaign has taken on % the frenzied quality of the previous do-or-die efforts on behalf of the budget and health care. Every Tuesday or Wednesday in the Roosevelt Room, Clinton meets for at least an hour with 10 to 20 undecided House members from both parties. The goal is to meet all waverers by the end of October. Once a week, Bentsen, Vice President Al Gore, Trade Representative Mickey Kantor and economics counselor Bob Rubin invite to Washington 100 business and opinion leaders -- mostly handpicked by undecided House members -- to learn more about the pact. Every visitor receives a follow-up note from the President and a call from someone in the NAFTA "war room."

White House lobbyist Howard Paster, meanwhile, has drafted Cabinet officers into a "shadow whip" system aimed at turning the undecided around. On "even" weeks, agency chiefs meet with three undecided members; on "odd" weeks, they are deployed to at least one fence-sitter's congressional district to make speeches, attract local press and provide "cover" for the lawmaker to vote yes.