Now he's waltzed into the leadership of the Liberal Democrats unopposed, but with a band of just 12 MPs.
At 74, he's his party's oldest ever leader. He's six years older then Jeremy Corbyn and three years older than Donald Trump.
In fact, he's the oldest leader of a UK political party since Sir Winston Churchill, who was 80 when he stepped down as Conservative leader.
Sir Vince started his political career in the Labour Party, as a councillor in Glasgow and then parliamentary candidate in York in 1970.
He joined the breakaway SDP in the early 1980s and eventually became a Lib Dem when the party merged with the Liberal Party in 1988.
In the 1970s, he was a special adviser in Whitehall to John Smith, who later became Labour leader. And before becoming MP for Twickenham in 1997, he was chief economist for Shell.
As a keen ballroom dancer, it's perhaps not surprising he's a romantic at heart. Since his first wife died and he remarried, he has worn both his wedding rings.
He'll certainly need all his charm to woo voters in the months and years ahead. His leadership will no doubt be defined by his party's ability to influence the Brexit process.
He faces daunting challenges. For a start, now the Lib Dems are no longer the third biggest party in the Commons, their leader is rarely called during Prime Minister's Questions.
Secondly, according to party grandees, he needs to concentrate on big issues, like Brexit and the economy, and not get drawn into rows over issues like gay sex, as his predecessor Tim Farron did.
"His tremendous advantage is his experience, so his age isn't a drawback," said a grandee who worked with Lib Dem leaders Paddy Ashdown, Charles Kennedy, Sir Menzies Campbell and Nick Clegg.
On Brexit, Sir Vince has expressed the controversial view in recent weeks that it may not go ahead. And he wants a second referendum.
"I'm beginning to think that Brexit may never happen," he said earlier this month. "The problems are so enormous, the divisions within the two main parties are so enormous I can see a scenario in which this doesn't happen."
On the economy, his supporters claim he predicted the 2008 financial crash coming. Now he thinks income tax should rise to pay for health and social care.
He has represented his party at PMQs before, with spectacular success, notably in November 2007 when Gordon Brown was in trouble over party donations, the Northern Rock crisis and other problems.
"The House has noticed the Prime Minister's remarkable transformation in the past few weeks from Stalin to Mr Bean, creating chaos out of order, rather than order out of chaos," he said, prompting howls of laughter from MPs on all sides.
Sir Vince's supporters in his party claim his five years as business secretary in David Cameron's coalition government make him the Lib Dems' best qualified leader of modern times.
They point out that his reputation as a wise economic guru and sage means he is constantly in demand for TV and radio interviews, which will greatly raise the profile of his party now he is leader.
But his critics claim there are serious blemishes in his record in the coalition government too, the most obvious being the Lib Dems' tuition fees betrayal when he was the Secretary of State responsible for the U-turn.
He also blundered when he told undercover reporters he had "declared war on Rupert Murdoch" in his BskyB takeover bid, forcing David Cameron to strip him of his responsibility for the bid and all media issues.
As Lib Dem leader, however, it is Brexit that Sir Vince is now about to declare war on. And with his profile already much higher than Tim Farron's, Remainers will see his election as a boost for their fight.
But how long will Sir Vince stay on taking the lead in his party? His political dance partner, new Lib Dem leader Jo Swinson, is half his age at 37 and it's thought he'll take a bow and let her step up before the next election.
Away from politics, his romantic instincts aren't just confined to ballroom dancing. Less well known than his appearance on "Strictly" is the fact that he has become a romantic novelist. Yes, really.
After writing several books about the economy, his first novel Open Arms, said to be a political thriller and love story set in a post-Brexit future, is due to be published in September.
Asked in a recent interview if it's about "sex and political intrigue", he said: "It is not actually about sex. The sex is very discreet, it is not going to win the bad sex award."
So if you thought the 74-year-old new Lib Dem leader was just a stuffy old economist obsessed with Brexit, you'd be wrong. It seems he's also a racy romantic.
As they might say on "Strictly": Cha, Cha, Cha!
