SO FAR THIS WEEK, President Obama has been called potentially "worse than Nixon" on freedom of the press issues, been accused of running an administration guilty of "outrageous, totally inexcusable" conduct, and has endured calls for the proverbial head of his handpicked attorney general, Eric Holder.

Rush Limbaugh's at it again?

Not exactly. During arguably the worst news cycle of his 52 months in the Oval Office, Obama suffered those verbal broadsides from liberal commentators and journalists such as the lawyer in the 1971 Pentagon Papers leak case and from Carl Bernstein, the reporter who helped break open Richard Nixon's Watergate scandal.

Make no mistake, the loudest voices calling for sweeping probes of Obama and even impeachment - among a few hard-core conservatives, anyway - are still his sore-throated critics on the political right, on talk radio and on Fox News.

But the sharper-than-usual blasts this week from liberals - especially on news that Holder's Justice Department conducted a broad and potentially chilling probe of phone calls to journalists at the Associated Press - may prove more critical. The controversies may determine whether Obama has any remaining chance of pursuing an ambitious progressive agenda of immigration reform and gun-safety laws - or if he's just the latest president with a cursed second term.

"I get no sense that liberals are rallying behind him," said Michael Smerconish, the Philadelphia-based radio host who just launched a new morning political show on the XM/Sirius satellite radio channel POTUS. Yet he also joins other experts in sensing that the controversies are not yet a game changer, and that both liberals and conservatives will eventually return to their usual battle stations.

At a Rose Garden news conference yesterday, Obama brushed off critics from both the right and left who've questioned whether probing journalists' phone records and reports that IRS workers targeted tea-party groups for extra scrutiny meant that he was at least headed down a Nixonian path, if not quite approaching the crimes of the Watergate scandal.

"My concern is making sure that if there's a problem in the government, that we fix it," the president said. "That's my responsibility. And that's what we're going to do."

It's important to note that the three issues that have dominated TV cable news and talk radio for the last week are not in any way created equal.

* The Benghazi controversy about the aftermath of an attack on a U.S. diplomatic mission in Libya continues to smolder on the far-right side of the dial, as allegations that whistle-blowers were punished or that changes were made to TV talking points typically fall apart as soon as they surface.

* The IRS scandal is clearly the most serious, and the most serious political threat to Obama, raising disturbing questions about whether conservative groups were singled out for aggressive tax scrutiny solely because of their political beliefs. This boondoggle has re-energized moribund tea party groups, and provoked calls for investigation from liberals. Obama has launched an effort to contain the blame to midlevel bureaucrats in one office in Cincinnati and to get ahead of the scandal by ousting the acting IRS commissioner.

* The AP scandal - centering on the sweeping Justice Department probe of the AP wire service over its sources on a story about a foiled terror plot in Yemen - is the one that has provoked the most sustained outrage on the left, even leading stalwarts like Esquire political blogger Charles Pierce to call for Holder to get sacked.

But it's important to note that the split among liberals over Obama's record didn't start last week. Since early in the president's first term, one faction of progressives - exemplified by the blogger and author Glenn Greenwald - has hammered Obama over broken promises on civil liberties such as failing to close the Guantanamo Bay detention camp and increasing targeted drone killings abroad, including of two U.S. citizens.

The attorney who battled the Nixon administration and won publication of the leaked 1971 Pentagon Papers, Joseph Goodale, has authored a new book called Fighting for the Press: the Inside Story of the Pentagon Papers and Other Battles, in which he warns that Obama will be worse than Nixon on press freedom related to national security if his administration continues to prosecute whistle-blowers at an unprecedented rate.

"He got off to a really bad start," Goodale, who calls himself "an Obama supporter," said in an interview. And he said he is deeply concerned that the White House is preparing to prosecute Julian Assange, the founder of the site WikiLeaks that publishes leaked, classified documents.

But Larry Sabato, the University of Virginia historian and longtime observer of national politics, said that any liberal outcry is likely a blip on the political radar. In the long run, he said, Democrats will revert to minimizing any misdeeds or blunders by Obama, while Republicans will labor to pump them up and look for impeachment grounds.

"At most, it's a lover's quarrel - it will be over quickly," Sabato said of the president's liberal base. "There may be a little dissatisfaction, but this is a marriage."