At Britain's last election campaign, he was hailed as the most popular party leader since Winston Churchill, an unexpected star who upstaged the two dominant parties. Some even wondered whether he was the "British Obama."

Nick Clegg's meteoric rise transformed him from a relatively obscure leader of the left-of-center Liberal Democrats — Britain's third party and perennial "also-rans" — into deputy prime minister. Five years on, he may be headed for the political graveyard — paying for his decision to enter a marriage of convenience with the ruling Conservative Party.

The Lib Dems are bracing themselves for a disastrous election, and Clegg, 48, faces the humiliating prospect of losing his own seat in Parliament. Many have not forgiven Clegg for breaking his pre-election pledge to oppose any increase in university tuition fees. Just months after the 2010 election, the Conservative-led government that he joined announced those fees would triple to 9,000 pounds ($13,600) per year.

"He didn't stand by his guns. Now he's gone to government, people have seen the other side of him," said Tony Lamb, a 57-year-old butcher in the constituency of Sheffield Hallam, where Clegg is fighting to keep a seat he's safely held for two terms. "People think he's just somebody's puppet, making up the numbers. That's all he's done."

That harsh judgment sums up the views of many voters who have turned their backs on Clegg, whose fall from grace has been as spectacular as his rise was sudden. As Britain heads into its most unpredictable election in years, the reversal of the Lib Dems' fortunes is a stark reminder of the volatile coalition politics that almost certainly lies ahead.

Polls predict that neither Prime Minister David Cameron's Conservatives nor their main rival, the Labour Party, will win outright in Thursday's general election. Most Britons expect some coalition with smaller fringe parties in the mix. But in 2010 the field was much less open, and Clegg appeared the fresh, authentic outsider as he took on his more established rivals.

A standout performance in a TV debate brought unprecedented support for Clegg and the Lib Dems, and when the Conservatives failed to win a majority, Clegg became kingmaker. But being the junior partner in the ruling coalition — Britain's first since World War II — meant the Lib Dems had to go along with Tory-led austerity policies, a move that alienated supporters and tarnished Clegg's reputation.

Soon, the man who sparked "Cleggmania" became "Calamity Clegg" — the target of vitriol around British campuses.

"People were queuing around the block voting for him the last time," said Sam Matthews, 22, a recent graduate. "There was a real feeling of an alternative. But we've lost all that sense of hope.

"I don't know how any student can vote for him again," he added. "He's saddled all of us with debt, thousands and thousands of pounds."

Matthews says he will likely vote for the Green Party — one of several former outliers, including the Scottish nationalists and the right-wing, anti-Europe UK Independence Party. They have all gained ground as the Lib Dems plunged.

The Liberal Democrats are expected to lose as many as half of their 56 seats in Parliament. Polls suggest that Clegg is in danger of losing the race in his constituency, a wealthy, hilly suburb of the central English city of Sheffield that has been held by the Lib Dems since 1997. The race there will be one of the most closely watched on election night.

If Clegg is worried, he and his party machine are not showing it. Campaigning with his wife in a Sheffield beer garden, he cheerfully delivered his well-rehearsed line that the Lib Dems are the only ones who can help the two main parties anchor Britain and ward off unpredictable coalitions with radical fringe parties.

"Only the Liberal Democrats now are the guarantee and the guarantors of stability and strength and fairness in the next parliament," he said, as dozens of party faithful cheered dutifully.

Clegg readily concedes that his compromises in government have come at a cost. He even issued a video saying "sorry" for his tuition fee debacle, which went viral as a musical parody. But he insists that his party is still best placed to hold the balance of power for a second time. That is less likely than in 2010, but still possible — another five years of a Conservative-Lib Dem coalition is considered one of the potential outcomes.

Some in Sheffield say they are ready to give Clegg a second chance. But others, like Matthews, have given up on him.

"His words are pretty much worthless now," Matthew said. "I'm sure he's not a bad person, but I don't feel sorry for him at all."

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