Britain is poised to move to the left. The United States has moved to the right. It may seem hard to reconcile the political tea leaves in the two English-speaking, best-friend nations, but there are similarities.

One common thread is that voters get fed up with any political party that has been in power a long time -- as the Conservatives have been in Britain (16 years) and as the Democrats were in the House of Representatives in the United States (40 years).

Another phenomenon found in both countries is that the opposition can gain by merely standing by and watching gleefully when the governing party begins to split into quarreling factions. In the United States, the Democratic Party struggles with divisions among old-fashioned Democrats (Ted Kennedy, Jesse Jackson), new Democrats (Bill Clinton, some of the time) and conservative Democrats (Sam Nunn). In Britain, the Labor Party is tentatively unified after years in the political wilderness, and the Conservatives are split with two-thirds stoutly moderate and one-third stoutly conservative, according to the vote of the Conservative MPs in the last week's leadership contest.

On the surface, America's Republicans may be more unified than at any time in modern memory. Gone is the liberal/Bull Moose/Dewey/Eisenhower wing. Gone is the Howard Baker/Jack Danforth moderate wing. What remains is the true-blue conservative wing with annoying yelping from the even-truer-even-bluer crowd on the far right. As conservative Bob Dole's tactics illustrate, for the 1996 presidential derby, the best way to silence the far, far right is to join them.

Prime Minister John Major did not play it that way in Britain. He confronted his far right and he prevailed -- just barely, in the view of most observers -- with one-third of the Tory legislators either voting against Major or abstaining in one form or another.

The wedge issue dividing the Conservatives was the extent to which Britain would place itself within the political framework of Europe. Much of the Conservative Party wants to enter the European Economic Community full force. Major wants it to be a bit in and a bit out. The Euroskeptic right wants Britain's sovereignty untouched and the country to remain aloof from odious continental political and economic entanglements.

Euroskeptics want no further discussion of a single European currency and they seek repatriation of powers already ceded to the European Commission in Brussels. Just as the words "United Nations" incite many Americans, so too does the word "Brussels" stir up a bit of rage in some British minds.

Major tried to straddle the intraparty conflicts as best he could until the grousing and sniping became more than he could abide. He resigned as party leader, forcing the referendum of Tory MPs that he managed to win narrowly.

In the United States, the analogue issue is isolationism. With the Cold War over, a segment of the Republican Party wants to "come home." The pitch is to abandon U.N. responsibilities and dump the NAFTA and GATT agreements. Before World War II, the Republican party was heavily isolationist. The prevailing view was that we were protected by the Atlantic and Pacific Oceans and that the intrigues of Europe and Asia were none of our business. Pat Buchanan's candidacy, coming from the far right, tracks both with that old Republican dogma and with the far right of the British Conservative Party.

In the final analysis, however, it wasn't just the question of the proper British presence in Europe that threatened Major's leadership role. Most of all, it was the polls. For many months, the Conservatives have been trailing Labor by as much as 30 points. Nothing concerns a politician more than the prospect of being driven over the political cliff by a floundering leader. Major is a Jimmy Carter-like figure of total decency and rampant charmlessness. As a devout centrist, he moves by nudges -- a bit to the left, then a bit to the right. He possesses none of Margaret Thatcher's commanding, defiant suspicion of everyone and everything. He's blander than bland.

Had the Conservatives been leading in the voter surveys, the revolutionaries of the right would have behaved. Poll figures translate into political clout both in Britain and in the United States. Had Bill Clinton established a Reaganlike following in the polls, his command of the Democratic Party would be unquestioned.

John Major may have, for the present, squelched the rebellion in his own party, but he hasn't united the Tories for the election to be held within two years. He has won the inning, but still trails badly in the game.

Tom Eagleton is a fomer U.S. senator from Missouri and a columnist for the Pulitzer Publishing Co.