If there is one belief that crosses all party lines, it's the notion that most voters are very responsive to the personalities of party leaders. From the obvious starting point that few voters take a detailed interest in policy, it is taken to follow that they will therefore be interested instead in matters of personality politics that direct impact upon almost no one. If the party leader is someone they would enjoy a beer with (or whatever the preferred metaphor may be) he's their man. The academic evidence for this notion is in fact extremely sparse - and it's interesting that two opinion polls in the last week would suggest the same.
YouGov's poll for the Sunday Times saw an increase of 17% on last month in David Cameron's personal approval rating. On Tuesday, MORI found Cameron's personal lead over Brown up 13% on last April, the previous time it asked the question. And yet ... the Conservative Party's ratings have not risen with the leader's ratings. YouGov puts the Conservatives on 41%, the same as last month. MORI puts the party on 42% - down 1% on last April.
Why wouldn't a party be dramatically more popular when its leader becomes dramatically more popular? Could it be that a leader's influence on his party's poll rating is more down to what he says and does on the real issues than the cynics like to think?