The Newark by-election, which the Tories won more comfortably than many expected, may represent the birth of a new trend in British politics: tactical voting against Ukip. Labour MPs who visited the constituency told me that they encountered a significant number of traditional centre-left supporters who held their noses and voted Conservative on the grounds that it was the best means of stopping Farage's party. One voter compared it to backing Jacques Chirac against Jean-Marie Le Pen in the 2002 French presidential election.
While some will regard this as an attempt by Labour to spin away a poor result, Conservative activists report having similar conversations. "I've never voted Tory in my life, but I'm not having those bastards [Ukip] getting in," one Newark resident was quoted as saying. Tactical voting for the Tories at least partly explains why Labour's vote fell and the Lib Dems' collapsed.
Ukip's decision to select Roger Helmer (whose past comments include describing rape victims as sharing "the blame" and homosexuals as "abnormal and undesirable") as its candidate was undoubtedly a factor. But it is also possible that the recent series of racist and sexist incidents has led the party at large to become toxic in the eyes of most voters.
As recent polling by YouGov has shown, 53 per cent of people now have a negative view of Ukip, up from 37 per cent in 2009. In Newark, the party polled particularly badly among women, with Survation's final poll putting them in third place on just 17 per cent, compared to 37 per cent among men. While the attacks on Ukip as "racist" have hardened its support among some groups, they have also limited its long-term potential. (For the same reason, eurosceptics worry that Ukip is contaminating the anti-EU movement. As support for Ukip has risen, support for withdrawal has fallen.)
For Nigel Farage, who acknowledges the importance of the party securing seats at Westminster, it is a worrying trend. If tactical voting against Ukip becomes a feature of British elections it will be far harder for the party to win MPs. To avoid being hamstrung by a low ceiling on its support, Ukip needs to detoxify its brand.