Party strategists have bet heavily on their assessment that voters think it is time for a change.
Perhaps simplistically, they hold to the notion that British political fortunes are governed by a pendulum. You often hear them criticise what they term the blue/red red/blue swings, but privately they accept it as a fundamental ‘law’ of political physics and have allowed themselves to be governed by this supposed law these last two years.
2010 will be one of those ‘Time for a Change’ elections, they have deduced.
From that deduction they moved on to suggest that the Conservatives (to whom in their estimate the pendulum has swung) have won the argument among the British public that they, the Conservatives, are the party of change.
The next step in the analysis was to presume that attacks on Conservatives or Conservative policies would thus position the Liberal Democrats as against change and therefore implicitly pro the status quo and, deep down in voter consciousness, pro-Labour.
Among leading Liberal Democrat MPs this conclusion may have been conveniently close to their political preferences, for others – and I think we may include Cable in this – it makes for an agonising and uncomfortable position.