In his defense of President Obama, White House press secretary Jay Carney is beginning to sound a lot like Ronald Ziegler, Richard Nixon's spokesman. Carney only has to use the word "inoperative," as Ziegler did when incriminating evidence surfaced that proved his previous statements untrue.

Following what appears to be a cover-up in the Benghazi attack, the Washington Post has obtained documents from an audit conducted by the IRS' inspector general that indicate the agency targeted for special scrutiny conservative groups with "tea party" and "patriot" in their names, as well as "nonprofit groups that criticized the government and sought to educate Americans about the U.S. Constitution."

IRS official Lois Lerner described the targeting efforts as "absolutely inappropriate," but said IRS actions were not driven by partisanship. How, then, would she explain why no groups with "progressive" in their titles were similarly targeted? Carney labeled Lerner an "appointee from the previous administration." In other words: Bush's mistake, not Obama's.

The Post's editorial board writes, "A bedrock principle of U.S. democracy is that the coercive powers of government are never used for partisan purpose." The board called for a full accounting. I doubt we'll get it. Take Benghazi.

ABC News first reported that the now famous Benghazi "talking points" used by U.N. Ambassador Susan Rice on five Sunday morning news shows were revised 12 times, deleting references to "the al-Qaida-affiliated group Ansar al-Sharia [and] CIA warnings about terrorist threats in Benghazi in the months preceding the attack."

Carney said Rice's initial claim -- that the attack grew out of protests over a video that insulted Islam -- was based on what was known to U.S. intelligence at the time. But as last week's testimony by three whistleblowers before the House Oversight Committee revealed, much more was known at the time.

Contributing to cover-up suspicions is the administration's continued stonewalling when asked to provide information on Benghazi. CNN sources acknowledge that "An email discussion about talking points the Obama administration used to describe the deadly attack on the U.S. compound in Benghazi, Libya, show the White House and State Department were more involved than they first said. ..." The American people deserve the full story.

The latest shocker, but probably not the last, is a report in the Daily Caller about CBS News Correspondent Sharyl Attkisson, who has "steadily covered the Obama administration's handling of the Benghazi terrorist attack in Libya," reportedly frustrating CBS News executives who claim her unrelenting coverage is "bordering on advocacy" on the issue.

Now, according to Politico, Attkisson can't get some of her stories about Benghazi on the air. Oh, did I fail to mention that CBS News President David Rhodes is the brother of Deputy National Security Adviser Ben Rhodes? Coincidental? Attkisson is reportedly in talks to leave the network. Is it because she chooses to behave like a real journalist instead of a cheerleader for Obama?

On Friday, Carney held a "secret briefing" on Benghazi for a select number of White House reporters, raising the ire of reporters not in the room. Is this what the Obama administration calls transparency?

Rep. Frank Wolf, R-Va., has asked House Speaker John Boehner to name a select committee to investigate the Benghazi attack with full subpoena powers that could place witnesses under oath. Boehner should. Meanwhile, House Oversight subcommittee Chairman Charles Boustany, R-La., has demanded the IRS turn over by Wednesday all communications containing the words "conservative," "patriot" or "tea party." And the IRS should.

Democrats now accuse Republicans of partisanship, claiming their motive is to damage Hillary Clinton's 2016 presidential prospects. If she has nothing to hide, transparency should enhance, not harm, her chances. We've learned more about Benghazi since her appearance before the Senate Foreign Relations Committee in January and she should be asked to account for it.

In 1972, Republican partisans initially accused Democrats of wanting to destroy President Nixon, but most were forced to acknowledge his culpability in Watergate once the facts became known. One of the Articles of Impeachment of Nixon concerned his misuse of the IRS to undermine political enemies.

Journalists should stop protecting President Obama and Hillary Clinton and do their jobs, like Sharyl Attkisson. Congressional Republicans should press for all the facts. That's their job.

Washington Examiner Columnist Cal Thomas is nationally syndicated by Tribune Media.