(FORTUNE Magazine) – Here are four reasons why Washington might actually deliver a tax cut in 1999: New House Speaker Dennis Hastert is determined to produce something positive for Republicans in the first year of the post-Newt era. Senate Majority Leader Trent Lott is under relentless pressure from a cadre of conservatives to lower taxes. President Clinton might embrace a tax cut as a way to change the subject from low-cut dresses. Vice President Gore is eager to disprove claims that he loves taxes even more than he loves the snail darter.

All that plus this: The federal surplus for fiscal 1999, as projected by the Congressional Budget Office, is $63 billion.

Of the dozens of proposals, the most distinctive come from Republicans who spent last year warming up for White House runs--Representative John Kasich of Ohio, who is talking about a 10% across-the-board cut, and Senator John Ashcroft of Missouri, whose plan to flatten taxes would also cut them by nearly $1.7 trillion. Ashcroft decided early this year not to run, but his plan remains the outer boundary of the tax-cut frontier. And each new GOP White House wannabe will bring along a new plan to trim rates. In the Senate, Republicans James Inhofe of Oklahoma, Spencer Abraham of Michigan, Rod Grams of Minnesota, and Rick Santorum of Pennsylvania already are pressing Lott to support a tax cut, while Representatives David McIntosh of Indiana and Jerry Weller of Illinois are pushing to place the issue at the top of the House agenda.

But the road to a tax cut must pass through the thicket of Social Security, and not only because President Clinton won't hear a word about lower taxes until the Social Security system is safeguarded. Right now the federal surplus is built on a gusher of money from the Social Security payroll tax, with even more coming this year when the 12.4% levy is applied to the first $72,600 of income, up from $68,400 last year, the largest increase in the wage base in 20 years. Subtract Social Security from the unified federal budget, and Washington is in the red by $54 billion.

So the Republicans' newest plan is to make a deal with the President they just impeached. The opening bargaining might go like this: We won't fight you on shoring up Social Security if you don't fight us on a tax cut. The most promising way in is a bipartisan plan to assure the future of Social Security by boosting the retirement age, cutting cost-of-living increases for upper-income beneficiaries, and creating some private savings accounts under the Social Security umbrella--accounts that presumably would be filled with money from a tax cut.

The likelihood now is that the tax cutters will think big, push hard, and at the very least come away with a few (not insubstantial) bones--the elimination of the marriage penalty, for example, or maybe the dismantling of death taxes. Conservatives want the estate tax gone by tomorrow morning, but they're ready to embrace a plan calling for an 11-year phaseout, a notion that many Democrats, heeding the entreaties of their wealthy contributors, quietly indicate they can accept. "The only people that this would bother are 77-year-olds who are afraid they might die too soon," says Grover Norquist, an anti-tax activist prominent in GOP circles. "For everybody else it's a winner." Tax cuts usually are.

DAVID SHRIBMAN is Washington bureau chief of the Boston Globe and a Pulitzer Prize-winning political reporter.