conservative wing of the Republican Party, but could open the way for Democrats to capture the political centre.

The House of Representatives began debating four articles of impeachment yesterday and was expected to approve them largely along party lines.

"I see it as a vindication of the social conservative wing of the Republican Party. I don't know of any conservative out there who doesn't want Clinton gone,'' said Greg Mueller, a political consultant who was press secretary for conservative columnist Pat Buchanan during his 1996 presidential campaign.

What has been striking about the debate has been the way most Republican moderates, who were originally expected to resist impeaching Clinton for perjury and obstruction of justice arising from his affair with former intern Monica Lewinsky, have joined the impeachment drive.

Public opinion polls continue to show that a sizeable majority of Americans oppose impeachment. But Republicans have been more anxious to heed the call of their own base supporters to impeach the president.

"The Republicans risk being viewed as a closed, highly partisan group dominated by their right wing,'' said Gary Jacobson, a political scientist at the University of California, San Diego.

"The Republicans are looking more and more like a wholly-owned subsidiary of the Christian right and it will hurt them in the longer term,'' he said.

Christian conservatives, especially from the South, have become increasingly important in the Republican Party over the past 10 years. They dominate the party in many states and have become a disciplined and reliable Republican voting bloc.

Christian conservatives have shown their strength by requiring the party to stick to a platform of total opposition to abortion under any circumstances.

Last year, rank-and-file conservative activists tried to pass a resolution that would have required the party to withhold financial support from any Republican who supported abortion rights. It was only defeated when top party leaders lobbied against it.

Democrats believe the Republican drift to the right has given them an opening to capture the political centre which they exploited in last month's congressional elections when they unexpectedly won five House seats.

"Fear of the right wing and what it might do to those who don't toe the line is driving developments in the Republican Party,'' said Democratic political consultant Bob Squier, who is expected to take a prominent role in Vice President Al Gore's presidential campaign in 2000.

"The outcome of the impeachment debate will only embolden the right to tighten the screws even more of their presidential candidates in 2000,'' Squier said.

"They have vacated the political centre and that represents a big opportunity for us,'' he said.

Republicans obviously dispute that analysis and do not fear political consequences of their votes to impeach Clinton.

"I have yet to find a Republican who really believes this will damage them in 2000,'' said Stuart Rothenberg, publisher of a political newsletter in Washington.