wo-party politics has served America well for most of two centuries. Stirrings last weekend in the Reform Party - formerly known as Ross Perot's Reform Party - may not threaten that system, but both Democrats and Republicans should pay attention and check their relevance.

Not since 1860, when the new Republican Party displaced the Whigs and elected Abraham Lincoln president, has a third party captured the White House or even come close. Theodore Roosevelt's Bull Moose candidacy had the unintended consequence of splitting the GOP vote and handing the election of 1912 over to Woodrow Wilson and the Democrats. Outsider candidacies such as that of George Wallace in 1968 have served only to consolidate the fringes.

Third parties can function as an alarm bell, however. Perot's 1992 candidacy drew 19.3 million votes with a message focused largely on deficit reduction and campaign finance reform. The deficits have been eliminated, and Congress should be in no hurry to risk their return with overly optimistic appropriations or tax cuts.

Campaign reform has also gained support but is still being blocked in Congress. Frustration with this money-dominated system based on the sale of influence is one of the few issues unifying delegates to the Reform Party convention in Michigan.

Indeed, one of the biggest problems facing the new reformers is agreeing on anything apart from their cynicism about the status quo and their opposition to the established power centers. At the Dearborn convention, some delegates were touting Pat Buchanan as a possible presidential nominee on the Reform Party line next year while others were pushing Ralph Nader.

At the urging of Governor Jesse Ventura of Minnesota, the convention chose Jack Gargen of Florida as national chairman over a Perot-backed candidate. Dissatisfaction with the major parties is not what it was in 1992, but the fact that there is a reform party underlines voters' continuing frustrations with the Democratic and Republican parties - frustrations those parties have earned.