It may be the million-dollar question in the IRS scandal: Why did former IRS Commissioner Douglas Shulman visit the White House at least 157 times?

There were 118 visits during 2010 and 2011, when targeting of Tea Party groups by the IRS was occurring. At a hearing on Capitol Hill, Shulman angered lawmakers by mentioning the Easter Egg Roll as he tried to explain why he was at the White House over 100 more times than former Secretary of State Hillary Clinton and other top officials.

Last night, Bill O'Reilly asked whether this could be the "smoking gun" in the IRS scandal in his Talking Points Memo (video above).

"What the heck was Mr. Shulman doing at the White House with that kind of frequency?" asked O'Reilly, noting that in his testimony to Congress, Schulman "was a wiseguy." O'Reilly said Shulman must be called back to testify again or someone at the White House should explain all of these visits.

He then talked to former IRS Commissioner Mark Everson, who served under George W. Bush from 2003 to 2007. During that time, Everson said he visited the White House only one time that he can remember on a "policy matter." He said he never talked on the phone with Bush or any other top White House officials about IRS policies.

In the next segment, O'Reilly had a contentious debate with Kirsten Powers, who said it's plausible that Shulman needed to be at the White House frequently because of the many tax implications contained in Obamacare.

"Are we supposed to believe that he was showing up twice a week in 2011 to scheme against the Tea Party!? Is that really what you're suggesting?"

O'Reilly said he doesn't know why Shulman was there, but there is "circumstantial evidence" that needs to be explained. Powers cautioned against trying to pin the IRS scandal on the White House without a "shred of evidence."

Watch the full interview below!