Leading article: An unseemly scandal and the lessons to be learnt

The White House was wise to ensure it put out the information before anyone else did. According to the official spokesman, George Bush's 2004 re-election campaign is busy returning thousands of dollars in contributions deemed to be tainted by association with the disgraced lobbyist, Jack Abramoff. Receipt of suspect money, however little, is the sort of scandal that can eat away at an American presidency.

The circumspection with which the White House dealt with questions about past meetings between Mr Abramoff and Mr Bush was also sensible. Even if neither the President nor the Republican Party has any record of personal encounters between the two, this does not mean that such evidence might not turn up in the course of an investigation. One framed photograph of the two shaking hands, one e-mailed allusion to a meeting discovered on a computer hard-drive, could expose Mr Bush or his office to accusations of lying.

Far better to say, as the White House did yesterday, that the two might have met at the occasional reception, just in case. Recent memory offers all too many examples of presidents, vice-presidents and would-be presidents being wrong-footed by their dealings with lobbyists. For the time being, however, the question is less about direct damage to Mr Bush - this is his second and last term as the president - than it is about the fall-out in the Republican Party and in Congress. Money is what makes the wheels of American politics go round. Fabulous amounts of it change hands in a multitude of ways.

Generous payment to a lobbyist is the tried and tested way of gaining access to politicians. Commercial concerns retain lobbyists to obtain advance information about legislation and then to campaign for or against it. The clout of pharmaceutical and medical insurance companies explains why the richest country in the world has no national health system worthy of the name. It is a seldom-breached law of US politics that the best-funded election candidate wins.

Sporadic efforts to rein in the power of lobbyists have failed. But the line between paid-for lobbying and straight bribery is at times very fine indeed. It is sadly typical that Jack Abramoff was caught on the wrong side of the law not in his day-to-day lobbying activities but for a casino venture where he falsely claimed to have commercial backing in order to draw in other investors and close a sale. While pleading guilty to this multi-million dollar offence, Mr Abramoff is asking for a host of others to be taken into consideration. He is expected to implicate perhaps dozens of members of Congress as part of a plea-bargain that will reduce his sentence.

When the shiny veneer is scraped off, the inner workings of American politics are not a pretty sight - and they never have been. Some distinguished careers will be wrecked. Given that Mr Abramoff is a Republican lobbyist, the Democrats will seek to make probity a central issue in this year's mid-term elections. Whether any bigger lessons will be drawn, though, is another matter.

However many individual scalps the bribery scandal claims, it may still not be enough for the Democrats to win control of the House later this year. Gerrymandering has been such that few truly marginal constituencies remain. And while there may be a new push for tougher laws on campaign financing, the lobbying fraternity will work to find new loopholes. In the end, the most damaging effect of the Abramoff scandal could be the way it rebounds on the President. Colourful revelations of high-level Republican corruption are the last thing Mr Bush needs at a time when his authority is under threat from so much else.