It's been a pretty rotten 12 months for liberals.

It was January 19, 2010 when Scott Brown won his shocking victory in the Massachusetts Senate race. And that proved to be only a foretaste of the beating that was waiting for Democrats in the fall.

A year ago, Democrats controlled the White House as well as supermajorities in the House and Senate. Now, the Senate is in filibuster gridlock, the liberal speaker of the House has been replaced with an arch conservative and Democrats hold fewer than 200 seats in the lower chamber for the first time since 1947.

And while liberals suffered as voters punished Democrats badly for the perceived excesses of the first-two years of the Obama era, the real pain for the self-styled "progressive" movement has come from the Democratic Party.

While many on the left thought that the battle between moderate Democrats and the party's liberal base ended with the defeat of Hillary Clinton in the 2008 primaries, the middle is reasserting itself with a vengeance as President Obama sprints to the political center.

Obama won the Democratic nomination by promising liberals that they would not need to engage in the kinds of compromise that had marked Bill Clinton's presidency. In 2008, Obama chided Hillary for voting for the Iraq war, lectured her on the problems with forcing people to buy health insurance and beat her up for supporting free trade.

On all of those points, and many more, Obama has snubbed his base.

The Obama foreign policy has taken George W. Bush's Iraq surge model (and his top commander) and applied it to Afghanistan. Obama also pushed through a health care law that mirrored what Hillary had proposed: compulsory insurance for all with subsidies for a cartel of huge insurance companies. Obama has also embraced free trade as a way to kick start the saggy economy.

There are certainly some things for liberals to celebrate in the Obama era.

His insurance law establishes health care as a government responsibility, if a court challenge to Obama's mandatory insurance provision doesn't ruin it all. And there are two very liberal new justices, both female, on the Supreme Court.

But Obama has broken faith with his base again and again.

Aside from the Afghan war, the left has watched in stunned amazement as Obama has continued to operate military prisons for enemy combatants in the war with radical Islam, fight a secret, global war using the CIA and aerial drone attacks and use extensive domestic surveillance to look for terrorists.

Obama's recent deal with Republicans to extend the current tax rates for all Americans for another two years caused such an uproar on the left that Obama held a press conference to scold liberals for being "sanctimonious" jerks who would rather Americans suffer than compromise on their core principles.

Some of these breaches have arisen from Obama coming to terms with the realities of the presidency. Having had less experience than any president in modern history, Obama likely did not understand the challenges posed by his lavish campaign promises.

That's certainly not to say that Obama has become a conservative. Certainly a president who nationalizes car companies, targets executive pay on Wall Street and brings down a regulatory hammer on the energy industry can hardly even be called moderate.

And if Obama succeeds in preserving his health care law against challenges political and legal, he will certainly go down in history as doing more to advance big-government liberalism in America than anyone since Lyndon Johnson.

But right now, Obama can't afford to look like that guy.

Many on the right saw Obama as a hard-core ideologue and predicted that he would be unable or unwilling to pivot after Democrats went down to an epic midterm defeat. But, starting with the tax compromise and continuing through the resurrection of Bill Clinton's economic advisers, Obama has been doing a very convincing impression of a moderate Democrat.

Obama may be just as liberal as he was when he promised to "spread the wealth around," but he also knows that there is no path to 2012 victory if he keeps talking like that. Having achieved big wins on health care and financial regulation in his first two years, Obama means to say and do what is necessary to win reelection and implement his agenda.

And that's what really hurts for liberals. They know he's right. If they tear him down for his apostasies, the left will only increase the chances of a continued Republican revival and a reprise of the Jimmy Carter debacle. The way to a larger victory is to support Obama even as he spurns them publicly.

The most painful message to what Robert Gibbs called the "professional left" is that their ideas are just not politically palatable in center-right America, despite their hopes that Obama's election marked a new political acceptability for their movement.

Instead of a flowering of the left, Obama's success in 2008 seems to have been an anomaly caused more by Republican failings. The 2010 results showed voters were no more comfortable with liberalism than they were before - maybe even less so.

Obama simply cannot afford to be publicly identified with the left anymore.

And with the stumbles this week as overeager liberals sought to pin the blame for the Arizona shootings on their political opponents, things look unlikely to improve anytime soon.

Chris Stirewalt is FOX News' digital politics editor. His political note, Power Play, is available every weekday morning at FOXNEWS.COM.

Chris Stirewalt joined Fox News Channel (FNC) in July of 2010 and serves as digital politics editor based in Washington, D.C.  Additionally, he authors the daily "Fox News First" political news note and hosts "Power Play," a feature video series, on FoxNews.com. Stirewalt makes frequent appearances on the network, including "The Kelly File," "Special Report with Bret Baier," and "Fox News Sunday with Chris Wallace."  He also provides expert political analysis for Fox News coverage of state, congressional and presidential elections.