`I have changed my party label but I have not changed my beliefs," Vermont's Senator James M Jeffords told journalists yesterday as he announced his defection from the Republican Party to become an independent in the US Senate.
In doing so he handed the Democrats a 51-49 majority and robbed Vice-President Dick Cheney of his precious casting vote.
Some would say he has come home.
Jeffords, a quiet-spoken maverick from a maverick state, Vermont, has for a long time been the most unlikely of Republicans, voting consistently on major issues with the Democrats.
In 1981 he was the only member of the House who voted against the infamous Reagan tax package and since then, in the Senate, backed Hillary Clinton's ill-fated health package, opposed the impeachment of her husband for high crimes and misdemeanours, and opposed the nomination of Judge Clarence Thomas to the Supreme Court.
Things did not get better with the election of George W. Bush whose tax package Jeffords did his best to water down.
And yesterday, setting out his reasons for defection, he listed just some of his disagreements with the President: abortion, the direction of judicial appointments, tax and spending, missile defence, energy policy and the environment, "and a host of other issues, large and small," he said.
Not least of those is education where he is one of the strongest opponents of Bush's pet project, vouchers.
The defection will put a prominent ally, Senator Ted Kennedy, into the chair of the education committee and make the administration's challenge significantly harder.
But the defection, although a humiliating blow to Bush's claims to be the champion of bipartisanship, does not change the political landscape in the way that it would in a European parliament precisely because of the reality illustrated by Jeffords's voting record.
Somewhat overshadowed by the defection, the Senate yesterday passed its amended version of the Bush $1.35 trillion tax package by 62 votes to 38.
The package still needs to be negotiated with the House, which has its own version, but reflects a $.25 trillion trimming of the White House's original vision.
The final compromise package was supported by 12 Democrats and all the Senate's 50 Republicans, including Jeffords, an important centrist who has contributed to most of the essential cross-party alliances that are needed to pass virtually all major legislation.
That reality was most vividly demonstrated in the eventual alliance which passed the campaign finance reform legislation against the wishes of both the Senate Republican leadership and the White House.
Jeffords will continue to play that role, albeit with a new affiliation, and probably as much a trial to the Democrat whips as he was to their Republican counterparts.
The truth is that Jeffords's defection will make no difference whatever to the number of votes in the Senate on which the President can count, any more than the frantic courting by Republicans yesterday of the maverick Georgia Democrat, Zell Miller, would if successful.
Miller, who regularly votes with the Republicans, was forced to issue a statement promising not to defect.
But he insisted both that he had no need to proclaim himself as an independent and that he expected to continue to vote Republican regularly.
SENATE rules also mean that any party needs a secure 60-40 majority to stop a single member on the other side from filibustering on legislation.
That threat of permanent gridlock on the administration's legislative programme led to the Republican leadership's willingness only a couple of months ago to agree new ground rules with Democrats about the sharing of time and minority rights. Republicans will now be glad that they did so.
But even if it does not fundamentally change the political balance of power, the defection does give the Democrats powerful new leverage to dilute, if not defeat, presidential legislation by passing over control of the speed and priority given to bills and, critically, to the approval of presidential nominations, most particularly to the judiciary.
It will test the extent to which Bush understands that to get his much-proclaimed bipartisan consensus on governing he will have to shift significantly to the left.
"The President will get his two priority objective, tax cuts and the education bill, and nothing else out of this Congress," one Republican complained bitterly yesterday, probably overstating the case.
But it will be more than galling to see the ousting of Orrin Hatch, the deeply conservative chair of the justice committee, by Patrick Leahy, also a Vermont man, before Mr Bush has been able to put in place the judicial counter-revolution that the right so hopes for.
His nominee for Solicitor General, Ted Olson, already in difficulty before the committee for his alleged role in a campaign by the American Spectator against Bill Clinton, will be an important test of Leahy's resolve.
Potential Bush nominees to the Supreme Court will be watching closely.
The elevation of Tom Daschle from minority leader to Speaker of the Senate will give the Democrats a significantly enhanced political soapbox from which to lambaste the administration.
But then, as the right-wing commentator, William Kristol, was quick to point out yesterday, putting a brave face on it, the loss of the notional control they had on the Senate gives Republicans someone else to blame if things do not go right for the administration.
psmyth@irish-times.ie