WASHINGTON – White House chief of staff Denis McDonough and other senior advisers knew in late April that an impending report was likely to say the IRS had inappropriately targeted conservative groups, President Obama’s spokesman disclosed Monday, expanding the circle of top officials who knew of the audit beyond those named earlier.

But McDonough and the other advisers did not tell Obama, leaving him to learn about the politically perilous results of the internal investigation from news reports more than two weeks later, officials said.

The apparent decision to keep the president in the dark underscores the White House’s cautious legal approach to controversies and reflects a desire by top advisers to distance Obama from troubles threatening his administration.

Obama spokesman Jay Carney defended keeping the president out of the loop on the Internal Revenue Service audit, saying Obama was comfortable with the fact that “some matters are not appropriate to convey to him, and this is one of them.”

“It is absolutely a cardinal rule as we see it that we do not intervene in ongoing investigations,” Carney said.

Republicans, however, are accusing the president of being unaware of important happenings in the government he oversees.

“It seems to be the answer of the administration whenever they’re caught doing something they shouldn’t be doing is, ‘I didn’t know about it’,” Sen. John Cornyn, R-Texas, told CBS News. “And it causes me to wonder whether they believe willful ignorance is a defense when it’s your job to know.”

Obama advisers argue that the outcry from Republicans would be far worse had McDonough or White House Counsel Kathryn Ruemmler told the president about the IRS audit before it became public, thereby raising questions about White House interference.

Still, the White House’s own shifting information about who knew what and when is keeping the focus of the IRS controversy on the West Wing.

When Carney first addressed the matter last week, he said only that Ruemmler had been told around April 22 that an inspector general audit was being concluded at a Cincinnati IRS office that screens applications for organizations’ tax-exempt status.

Carney said the audit was described to the counsel’s office “very broadly.”

But on Monday, Carney said lower-ranking staffers in the White House counsel’s office first learned of the report one week earlier, on April 16.

When Ruemmler was later alerted, she was told specifically that the audit was likely to conclude that IRS employees improperly scrutinized organizations by looking for words like “tea party” and “patriot.” Ruemmler then told McDonough, deputy chief of staff Mark Childress, and other senior advisers, but not Obama.

A new Pew Research Center poll shows 42 percent of Americans think the Obama administration was “involved” in the IRS targeting of conservative groups, while 31 percent say it was a decision made solely by employees at the IRS.

The IRS matter is one of three controversies that have consumed the White House over the past week. In each instance, officials have tried to put distance between the president and questionable actions by people within his administration.

As with the IRS investigation, the White House says Obama learned only from news reporters that the Justice Department had subpoenaed phone records from journalists at The Associated Press as part of a leaks investigation.

And faced with new questions about the deadly attacks in Benghazi, Libya, Obama’s advisers have pinned responsibility on the CIA for crafting talking points that downplayed the potential of terrorism, despite the fact that the White House was a part of the process.

Former White House officials say a president has little choice but to distance himself from investigations and then endure accusations of being out of touch, or worse.

“It’s a tough balance,” said Sara Taylor Fagen, who was White House political director for President George W. Bush from 2005 to 2007.

“With a scandal, there’s no way to win,” said Fagen, whom the Senate Judiciary Committee subpoenaed and sharply questioned in a probe of dismissed U.S. attorneys.

“There may never have been any wrongdoing by anyone in the White House, on any of these issues,” she said, “but once the allegations are made, you can’t win.”