Former senator Paul Tsongas says President Bush's astronomical approval ratings might help launch the Massachusetts Democrat's bid for his party's presidential nomination in 1992.

"If he drops below 80 percent, I won't run," the self-described "pro-business liberal" quipped this week.

In Washington to meet with friends and prominent Democrats -- including two potential presidential candidates, Sen. Lloyd Bentsen (Tex.) and House Majority Leader Richard A. Gephardt (Mo.) -- Tsongas said Democrats must recast the party's message to appeal to moderate voters because of Bush's high popularity.

"Those of us who have liberal credentials are better positioned {to do this} than those who are more conservative in their voting patterns," he said. "I'm not one who can be easily dismissed by those who are liberal in their social orientation."

Tsongas gave up his Senate seat in 1984 when he was diagnosed to have lymphoma, a form of cancer. He said his health is restored and that he will decide whether to run by the end of the month.

He has formed a campaign committee, scheduled a $1,000-a-person fund-raiser in Boston on April 11 and will travel to Iowa and New Hampshire soon. In addition, an aide said Tsongas has received more than $20,000 in unsolicited donations.

Tsongas, who said he does not want to mount "a symbolic campaign," acknowledged his uphill task. "If the president is losing sleep over me, it's measured in milliseconds," he said. "And that's not going to change for a while."