Last week I wrote a blog entitled: "Have the Balls bashers gone mad?"

This week I have to ask the question: is it really the Tory right that's gone mad? Taken collective leave of its senses? The non-stop chatter about whether or not Cameron will survive until 2015 and the endless speculation about whether it'll be Theresa May or Boris Johnson who succeeds him is bizarre - and the leadership-bid-that-never-was from unknown Tory backbencher Adam Afriyie was simply beyond parody. In fact, I find myself, weirdly, unusually and unexpectedly, coming to the defence of our poor prime minister.

Memo to Tory plotters and rebels: it ain't all Dave's fault. Nor will forcing the PM to fall on his sword to spend more time with his DVD collection save your party from defeat in the Euro elections in 2014 or the general election in 2015.

Don't get me wrong. I have long argued that David Cameron is a deeply overrated politician, and out of his depth on the economy in particular. His failure to win a majority in 2010, despite being up against a tired and hapless Gordon Brown is evidence of how unpopular the Tory leader is; the long list of U-turns he has since had to perform in office reveals a lack of basic competence and attention to detail.

But to pretend that the Tories would have done any better in 2010 under a more right-wing, less socially liberal candidate is pure bunk, belied by every study that's been conducted on the results of the last general election. And to believe that Liam 'freeze all spending despite the failure of auserity' Fox or Philip 'freeze all spending except in my own department' Hammond would win the party more votes than Cameron come 2015 is nothing short of delusional.

But what about Theresa May, I hear you ask? Yes, in the words of John Rentoul, "the attraction of a comprehensive-educated, Thatcher-like alternative who is tough on crime is obvious". Might she also help the Tories win back women voters? Maybe.*

Yet, as the Sunday Times/YouGov poll yesterday revealed, only 12% of voters think she would do a better job than Cameron, compared to 35% who say she'd be worse. Some of us haven't forgotten Catgate either.

It cannot be said often enough: the prime minister continues to outpoll both his party and the coalition. Yes, he and his allies are too "posh, male and white"; yes, the prime minister has been unable (unwilling?) to silence his backbench critics through the usual combination of charm, patronage and... intimidation.

The Tories' problems, however, are more structural than personal; more about policy than personnel. Thus regime change is, in a sense, irrelevant.

Perhaps the wilfully-blind Tory rebels should consider the following six questions.

1) How would replacing Dave with, say, Boris change the fact that the voting system is so skewed against the Tories that the party needs a double-digit lead over Labour in order to secure a single-seat majority in the Commons - especially after Conservative backbench rebels (and not Cameron) provoked the Lib Dems into opposing boundary changes?

2) How would replacing Cameron with Adam Afriyie change the fact that the Tories need to up their share of the vote at the next general election in order to win a majority - an achievement that was beyond even the ability of their heroine Margaret Thatcher at the height of her powers (in 1983 and 1987)?

3) How would replacing Cameron with Theresa May win over the three key groups of voters that Cameron failed to seduce in 2010 - public-sector workers, Scots and ethnic minorities?

4) How would replacing Cameron with Philip Hammond help the Conservative Party detoxify its brand in a country where 42% of voters say they would "never" vote Tory (compared to 30% for Labour)?

5) How would replacing Cameron with Michael Gove prevent a looming triple-dip recession, or give economic growth a much-needed boost? How would it cancel out the four-fifths of public spending cuts that are still to come?

6) How would replacing Cameron would Liam Fox stop the flow of Lib Dem voters to Labour? "Ed Miliband is finding it very hard to persuade voters to switch from Mr Cameron's party to his," wrote ConHome's Paul Goodman in December. "But he doesn't need to do so in order to nudge Labour's poll share, come 2015, into the mid-30s or higher: all he must do is to hold on to those Lib Dem defectors."

Do the rebels on the right have adequate answers to any of these six questions? Do they even recognise the existence of such awkward queries? Or do I a smell a bit of denialism on their part?

Look, I get why unhappy - and more 'traditional' - Tories look at the polls, look at the Eastleigh result, and focus their ire on Cameron and his 'modernizing', gay-marrying, Notting Hill ways. Change the leader, they wail, and we'll be able to give Labour (and Ukip) a good kicking. It's a seductive if simplistic proposition. But, for once, personality politics is irrelevant. The Conservative Party's problems are much wider and deeper - psephological, historical, geographical and, perhaps above all else, related to the state of the economy.

And what I don't get is how putting Boris, Theresa, Adam, Michael, Liam or Philip in charge, in Dave's place, will help solve such seemingly insoluble problems.

* For those on the right who automatically and patronisingly assume that putting a woman on the ticket wins over female voters, I have just two words: Sarah Palin.

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