Anybody who has been involved in an election campaign against the Lib Dems will be aware of their legendary capacity to be two-faced while talking through their collective rear end, as evidenced by Clegg's apology last week, niot for going back on a pledge but for making a pledge in the first place.
What he is saying is that not only is it perfectly reasonable for a politician to go back on a firm promise to the electorate, but by implication, the voters should never trust even the most explicit promises made by politicians.
Which makes today's statement that the Conservatives should stick to the Coalition agreement and consider some sort of wealth tax and House of Lords reform is doubly disingenuous.
Not only were neither point mentioned in the Coalition agreement, but it is the Lib Dems who are flouting the agreement by refusing to honour the part of the agreement which explicitly linked the AV referendium (which we have had) with constituency boundary changes (which we haven't because of Lib Dem opposition).
The hypocrisy is stunning.