It all began with a major loss of face over a referendum of the Lisbon Treaty, when nearly a quarter of his MPs defied his instructions to abstain on whether there should be a public vote, and three of his frontbenchers quit to join the rebellion.
A second slap in the face over the issue from his own party came when Lib Dem peers said they were going to ignore his troubled abstention policy and vote against a referendum when the matter comes to be debated in the Lords. A stance that apparently hasn't gone down at all well with those of their fellow party MPs trying to defend marginal seats.
A matter of days later, his much longed-for 'man of principle' image took another knock when he dodged a question tabled by a Spectator reader as to whether his position in favour of an in-out referendum on the EU (rather than one on the Lisbon Treaty) was going to be in the party's next election manifesto.
A reaction that seems to indicate that the allegedly "principled" policy has already been dropped, fuelling suspicions that it was only ever a lame ploy to get the Lib Dems out of their election promise to support a referendum on the renamed EU Constitution Treaty.
Facing accusations of a feeble first 100 days, next came Clegg's ill-judged claim that he had slept with "up to 30 women", during a discussion of his sexual history with GQ magazine.
And now, according to a report in the Independent on Sunday, it has emerged that after all his woes, poor Nikki Clegg may not be the real leader of the Lib Dems after all!
Hundreds of postal votes, arriving late due to the Christmas post, would apparently have meant Chris Huhne in fact won the race to succeed Menzies Campbell.
Mr Clegg beat his rival by just 511 votes out of more than 41,000 party members in one of the closest-run races in political history.
Yet as many as 1,300 postal votes arrived after the deadline of 15 December – and an unofficial check of the papers showed that Mr Huhne had enough of a majority among them to hand him victory.
Whatever next for 'Calamity Clegg'?