THE UK Independence Party (UKIP), once dismissed by David Cameron as a party of "fruitcakes, loonies or closet racists, mostly", now has its first elected MP. Douglas Carswell represented Clacton under Conservative colours before he resigned in August, defecting to UKIP and triggering a by-election. Yesterday his former constituents reelected this cerebral libertarian with a stonking 60% of the vote.

The party only narrowly missed out on a second win in Heywood and Middleton, where another by-election took place, this one caused by the death of the sitting Labour MP. Though victory in this suburb of Manchester had been thought beyond UKIP's grasp (the demographics are not especially favourable and the party had virtually no infrastructure locally), the party's candidate came within 617 votes of taking the seat from Labour. By-elections are by-elections. The relentless focus on one or two seats over a short period of time does strange things to results. Small parties without the resources credibly to fight national elections can concentrate those, and persuade voters to send a message to Westminster without worrying about a change of government. But more than most by-elections, the results from Essex and Lancashire are signs of something bigger. They look worst for the Conservatives, who lost half of their vote-share in Clacton, and the Liberal Democrats, who lost their deposit. Mr Carswell's success may inspire other Tory MPs to follow his lead (one, Mark Reckless, did so two weeks ago, and will contest his Kent seat of Rochester and Strood in a by-election there next month). He will spend his coming months in Parliament broadcasting UKIP attacks on his former party over difficult subjects like the EU. For some Tory members and supporters, his election may be the final nudge they need to jump ship. In practice, however, the results are most disappointing for Labour. Governing parties often do badly in by-elections. But Labour has been in opposition for over four years. In Clacton, which the party held (albeit on different boundaries) until 2005, it obtained just 11.2%; a fall of more than half since the 2010 election, itself the party's second-worst since 1918. Most dismally, in Heywood and Middleton the party narrowly won where it should have roundly trounced UKIP. Former Lib Dem voters, on whom Labour is relying to carry it over the line next year, switched in large numbers to Nigel Farage's party. The lot of Ed Miliband, already under attack for his party's lacklustre conference and broader underperformance, becomes yet more difficult this morning. He is due to address his MPs on Monday. Mr Farage said yesterday that a win in both seats would be the political equivalent of the eruption of Krakatoa. But that suggests that these by-elections were isolated occurrences, which they are not. Your correspondent submits that a comparison to Etna makes more volcanological sense. UKIP now looms over the Westminster landscape, emitting regular burps of smoke to remind other parties of its presence. It may win Rochester and Strood next month. At next year's general election it will probably pick up a handful of seats (Peter Kellner of YouGov suggests that the number could be up to ten), but will exercise its greatest influence by affecting the result in dozens more; in some places benefiting Labour, in other the Tories. As a result, UKIP is now rarely far from strategists' minds and will shape the character and outcomes of the main parties' campaigns next year. Mr Cameron's reference to "fruitcakes, loonies and closet racists" never looked so glib.