As the Republican-controlled Senate humiliated President Clinton by rejecting the nuclear test ban treaty he signed three years ago, he is seen as entering the "twilight" of his presidency. He is said to be taking it hard.

As his foreign and domestic policy initiatives are rejected one after the other on Capitol Hill, he is forced to watch the country's attention switch away from him to the race for his successor and his wife's bid to become a New York senator.

As a sign of his darkening mood, the political columnists seized on a recent Associated Press report head ed "Clinton golfs alone under rain and darkness". A striking contrast to the sunnier days when the TV cameras would catch him in a golf cart with cigar in mouth and an arm around a powerful insider figure.

For his critics, he is getting the come-uppance he has richly deserved but which up to now he has been able to dodge with his legendary good luck and his Arkansas charm. Charles Krauthammer, one of these critics, wrote in the Washington Post last week: "But as his presidency wanes, as his power erodes, as respect for him evaporates, as the legacy he lusts for recedes over the horizon, the charm wears thin and we are left with the real Clinton - bitter, angry and flailing."

This uglier side of Mr Clinton was on view at press conferences where he lashed out at Republican senators for voting down the test ban treaty. He accused them of a "new isolationism" and of "partisan politics of the worst kind", which would threaten the security of America.

His anger and frustration were understandable. The political leaders of Britain, Germany and France had taken the unprecedented step of writing an article in the New York Times appealing for the ratification of the treaty and Mr Clinton had failed to deliver - not just by a few votes but by 17.

The other side of the story is that the president and his administration badly bungled the attempted ratification. He had overestimated his ability to win over Republican opponents of the treaty, which many see as genuinely flawed and dangerous for US security.

The Senate Democrats also walked straight into a trap set by the small number of Republican diehards determined to kill the treaty while the Secretary of State, Madeleine Albright, and the Secretary of Defence, William Cohen, made a poor show of selling the treaty at the admittedly brief pre-vote hearings.

The rejection was a humiliation for the president which resounded around the world, but on the domestic front, Mr Clinton is also continually thwarted in his efforts to carve out a legacy for himself in safeguarding the social security system, stricter gun controls, raising education standards and anti-tobacco laws.

Mainly this is due to Republican majority opposition but his own Democrats also humiliated him by refusing to give him so-called "fasttrack authority" to negotiate a new world trade agreement. The negotiations begin next month in Seattle and Mr Clinton has not even dared to seek the authority which previous presidents were always given.

The strain of this looming "lame duck" phase in his presidency may have had something to do with the extraordinary lapse while in Canada recently of referring to the two sides in the Northern Ireland peace process as "like a couple of drunks" who couldn't kick the habit. His swift apology helped defuse the rumpus caused by his controversial remarks but many Irish-Americans who are following the ups and downs of the peace process were even more irritated by the president's complaint that he has "spent an enormous amount of time trying to help the people in the land of my forebears in Northern Ireland get over 600 years of religious fights".

While granting that the president has given more time than any other to seeking a solution, the Irish-Americans were dismayed that he was portraying the conflict in outdated religious terms.

The final year of any presidency is always hard as the incumbent tries to ensure a list of achievements which will get his name in the history books. For Mr Clinton, last year's impeachment vote by the House of Representatives has ensured that he will go into the history books linked with Monica Lewinsky even if the Senate later voted against dismissing him from office.

With the test ban treaty down and Mr Clinton squabbling almost daily with the Republicans over this year's budget, the fall-out from that traumatic period becomes more evident. The economy may have boomed for the seven years of the Clinton presidency but to his frustration, he gets little credit.

He badly wants the Vice-President, Al Gore, to win next year and carry on the Clinton agenda but has to endure Mr Gore's signals that he wants to stand on his own feet in a campaign where "Clinton fatigue" is undermining him in the polls.

It is not surprising that the press is getting reports of a president who is having to cope with "foul moods" which assail him some mornings. He recently confessed to a gay rights group in New York that, "On one side there's the light forces and the other side there's the dark forces in our psyche and make-up and the way we look at the world . . . if the scale tips dark, even a little bit, things turn badly for people and those with whom they come in contact."

The president's aides point out that his foreign policy record is still an honourable one. The US contributions to the liberation of Kosovo, the revitalisation of the Middle East peace process, ending conflicts in Africa from Sierra Leone to the Con go and helping to stop slaughter in East Timor are cited.

While it may be fashionable now to dismiss a "lame duck" presidency, Mr Clinton is still the leader of the most powerful country in the world. He has shown that he can bounce back from adversity and his standing with the American public is remarkably high after seven bruising years in office.

After several years of trying to govern from "the centre" and seeking consensus on Capitol Hill to get his agenda approved, he is now taking a more aggressive approach with Republicans, portraying them as "isolationist" in foreign policy and lacking compassion for the less fortunate in America who have been left behind by the economic boom.

He can no longer run for office but he is not going to go quietly.