As seen on Fox News Channel's "Happening Now" on May 26:

KARL ROVE, FOX NEWS CONTRIBUTOR/FORMER GEORGE W. BUSH SENIOR ADVISER

[There are one of two things going on here:] Either Joe Sestak is a liar and he's not telling the truth about this, or somebody inside the White House committed a felony. 

[Federal law] 18Usc211 says that a government official cannot receive anything of value in return for a promise of government employment. That is to say, you can't offer somebody a government job in return for receiving anything that could be considered a benefit. Well, you know, a clear path to the nomination for your political ally is clearly something of benefit, so to resolve this, we got to have -- Joe Sestak has got to step forward and say here's who made the offer and here's when they made the offer to me. And then the White House has to make that person available and explain why this isn't a violation of law. 

And you know, it's not enough to depend upon the White House to simply to say, well you know, we've looked into it and there's not a problem. Who said what to whom and when did they say it?And who knew about this offer being made? Did the president, for example, know about an effort to, in essence, bribe Joe Sestak [to get] out of the race? And we can't allow stonewalling. The people of Pennsylvania and the American people deserve to have answers to these questions. 

What we do know was that Joe Sestak was asked the question, "were you offered a job in the administration in return for pulling out?" And he said, "yes." So again, it goes back to the fundamental question, who said what to him? And he needs to be forthcoming in that. And then we need to check with the White House to have them make that person available and put their explanation on it. I doubt that it was said in sort of a hidden way so that Joe Sestak assumed. He was emphatic when he answered the question yes, he was offered a job, a post in the administration if he withdrew from the primary. That's pretty straightforward and direct. Who made that offer to him?

You have the chairman of the Democratic National Committee saying yes, we need to get to the bottom of it. Yes, we do. I mean, this is a bribe. And the idea that somebody inside the White House would have tried to bribe a candidate with an offer of government employment, again, I repeat, it's either Joe Sestak telling a lie -- in which case the White House needs to be absolved of any wrongdoing -- or he's telling the truth, in which case, we need to know who committed, potentially, a felony at the highest levels of the White House. 

The reason I'm concerned about this is, we already have a sense of callousness inside the White House about these kind of questions. The White House chief of staff, Rahm Emanuel, was in Congress in 2005 and was given e-mails from the Republican Congressman Mark Foley in which he was trying to sexually prey upon underage teenage male Pages, and then-Congressman Rahm Emanuel sat on those e-mails. He had a moral obligation to give them over to the Page Committee, which is charged with protecting the safety of the Pages or to turn them over to the Ethics Committee which looks at violations of law by Congress. Instead, he held on to them for a year, content to let, in the meantime, Congressman Foley prey on underage male Pages perhaps, in order to use it as a political issue in the closing days of the 2006 campaign. 

That kind of moral callousness in the White House chief of staff gives me pause as to why we can't trust the White House to just sort of say 'we looked into it and there's no problem.' Who talked to whom and what did they say? And let's have Joe Sestak's version and let's have the White House version and let the people decide whether or not there's a problem. 

Karl Rove joined Fox News Channel as a political contributor in February 2008. He also currently serves as a columnist for the Wall Street Journal. Mr. Rove helped organize the political-action committee American Crossroads. His latest book is "The Triumph of William McKinley: Why the Election of 1896 Still Matters" (Simon & Schuster, 2015). Follow him on Twitter @KarlRove.