The headline “An Elephant Crackup?” in Sunday’s New York Times is actually about real elephants, not about politics at all, but it could equally have referred to the current fortunes of the Republican Party.

With mid-term elections now just four weeks away, on 7 November, Republican control of the US Congress is looking seriously threatened.

The combination of Mark Foley’s disgrace and Bob Woodward’s new Iraq book has meant a very bad couple of weeks for President Bush’s party.

Congress is like our federal parliament in some ways: a Senate with six-year terms, and a House of Representatives with single-member districts (although two-year terms rather than three, so only a third of the Senate elected each time). But its dynamics are quite different.

In the House of Representatives the Republicans currently hold 232 of the 435 seats, so a loss of only 15 seats would cost them their majority. Since two recent polls, by CNN/Gallup and ABC News/Washington Post, show swings to the Democrats of about 12.4% and 8.2% respectively, one might think that’s pretty much a foregone conclusion.

That’s not how the American system works, however. Because politicians draw the boundaries themselves, there are very few marginal seats, and the perks of office allow incumbents to entrench themselves in a way Australian MPs can only dream about. Most seats only ever change hands when an incumbent retires.

The most recent scorecard from Congressional Quarterly lists 350 of the seats as safe. Of those regarded as being in play, four Republican seats are judged as leaning to the Democrats, and another 13 as “no clear favourite”.

That suggests control of the House is still up for grabs. The betting market, however, has swung against the Republicans, with the latest odds at online trading exchange Tradesports giving them only a 40% chance of retaining a majority.