After his election as Conservative leader in 2005, it was famously David Cameron's mission to "detoxify" his party's brand. Cameron aimed to convince those groups repelled by the Tories' conduct in government - ethnic minorities, northerners, Scots and LGBT voters - to take another look at them. It was his failure to fully achieve this aim that prevented his party winning a majority in 2010. Just 16% of ethnic minority voters voted for the Tories and the party won just one seat in Scotland and just 20 of the 124 urban seats in the midlands and the north.
Since then, matters have little improved as, under the guidance of Lynton Crosby, Cameron has largely abandoned modernisation and retreated to the core territory of Europe, immigration and welfare. It's notable, then, that today's Ipsos MORI poll shows that the Tories remain the most toxic of the three main parties. Asked whether they like or dislike the Conservative Party, 57% say that they dislike it, compared to 43% who dislike Labour and 47% who dislike the Lib Dems. Just 39% say they like the Tories, compared to 49% who like Labour and 43% who like the Lib Dems.
It's findings such as this that show why Labour could win the next election despite the unpopularity of Ed Miliband (whose net satisfaction rating has reached a new low of -27, compared to Cameron's -17) - the party is fishing in a larger pool.
The Conservative, who plan to frame the next election as a presidential contest ("do you want David Cameron or Ed Miliband as your prime minister?"), console themselves with the thought that Miliband's lack of appeal will ultimately drag Labour down. But while Cameron's greater popularity could save the day for the Tories, it is complacent of the party to assume as much. History shows that a well-liked (or, more accurately, less disliked) leader is no guarantee of electoral success. In the final poll before the 1979 election, Jim Callaghan enjoyed a 19-point lead over Margaret Thatcher as "the best prime minister" but that didn't stop the Conservatives winning a majority of 44 seats. Similarly, in the 1970 election, Harold Wilson's personal lead over Ted Heath (a 51 per cent approval rating compared to one of 28 per cent for Heath) didn't stop Labour going down to a decisive defeat.
In 2010, David Cameron's lead over Gordon Brown wasn't enough to deliver the Tories a majority. In 2015, his lead over Miliband may not be enough to deny Labour victory.