BRISTOL, England - After a lifetime on the political sidelines, Nick Clegg finally knows what it means to be in government: People hate you.

Angry students burn him in effigy. Former supporters say he makes them sick to their stomachs. Famous actors say they're profoundly disillusioned.

It's been a head-spinning year for Clegg, the fresh-faced leader whose charm and promise of a new way of doing things took the political world by storm and brought some much-needed zest to a stuffy election campaign last spring.

His insurgent Liberal Democrats finished third and got to play kingmaker in the new government. But Clegg's decision to go for an unlikely marriage with Britain's Conservatives - and become deputy prime minister - now threatens to sink his party.

Not eight months into a coalition government, the "Lib Dems" are bleeding support, their poll numbers so low that they would struggle to win just a handful of seats in Parliament if an election were held today.

Clegg's problems have something in common with President Obama's experience of late: Both have angered their liberal base with compromises of governing that have fallen far short of campaign promises.

But for many Lib Dems, anger is compounded with disgust at finding their historically left-leaning group yoked to a party of the right. Numerous party stalwarts are horrified by Clegg's assent to a sweeping Tory plan to cut public spending and welfare benefits, which they fear will put the most vulnerable in society at risk during already hard times.

For disaffected supporters, betrayal has become a byword to describe the party leaders who they feel have sacrificed principle for a taste of power, which is proving somewhat bitter.

"The party is going through a painful rite of passage," said Stephen Williams, a Liberal Democratic member of Parliament from Bristol, in southwest England. "We've had the luxury of always being a small opposition party and having a more purist outlook on how things should be, and people found that easier to agree with. But now we're in government ... and we're finding out what it's like to be on the receiving end of vitriol and anger."

Outrage peaked this month when a majority of Liberal Democratic lawmakers joined the Conservatives in voting to increase university tuition fees, breaking a campaign pledge not to do so.

"I can't believe they've done it," said Jodie Touhy, 31, of Bristol.

Touhy, a stay-at-home mother, has voted for the Liberal Democrats in every election since she turned 18. She liked that they opposed the invasion of Iraq; she agreed with their stands on helping the poor and their support for women's rights.

When no party emerged with a majority in Parliament in the May election, surely, Touhy thought, the Lib Dems would throw in their lot with the Labor Party for a grand coalition of the left.

"I actually felt physically sick when they went in with the Tories," she said. ". . . It was horrible."

Touhy has defected to Labor, and she's not alone.

Several Liberal Democratic local government councilors have renounced their party membership. Actor Colin Firth (The King's Speech) called the vote on tuition fees a "profoundly disillusioning" moment that has made it difficult for him to continue backing the party.

One recent poll showed support for the Liberal Democrats plunging as low as 8 percent, a shocking slump from the 22 percent of the vote the party garnered in May.

Back then, some Lib Dems bragged that after Clegg's star turn in Britain's first televised election debates, their party might even muscle aside Labor as the voice of the center-left. That boast looks hollow now, with Labor and the Tories close to even, at about 40 percent, and the Liberal Democrats fumbling in the basement.

What's ironic is that the party's numbers have fallen even as a majority of Britons appear to approve of the coalition government's overall performance. Critics have taken to mocking the Liberal Democrats as the Tories' "human shields," who receive all the flak but none of the praise.

"It has been deeply frustrating that we aren't getting the credit for some of the liberal things the government is doing," such as scrapping the national ID cards instituted by the previous Labor government, Williams said. "Things that ... are good, the coalition government gets the credit for. Things that are bad, the party gets blamed."