Host Bill O’Reilly speaking with James Steinle and Elizabeth Sullivan, parents of Kathryn Steinle, during an interview by satellite for “The O’Reilly Factor” on July 13. (Fox News Channel via Associated Press)

Bill O’Reilly has seeded a compelling conflict of interest on his eponymous Fox News program. This month, he began advocating something now known as “Kate’s Law,” a proposal to slap a “mandatory” five-year prison sentence on undocumented immigrants who are deported and “return to the United States.” A petition on BillOReilly.com is seeking signatures for the effort.

The idea is noble — to guard against a repeat of the San Francisco tragedy in which an undocumented and oft-deported immigrant — Juan Francisco Lopez-Sanchez — is alleged to have killed 32-year-old Kate Steinle. As the force behind “Kate’s Law,” O’Reilly promotes the proposal on air; as a Fox News host, he reports on the proposal’s progress on Capitol Hill.

On the latter front, O’Reilly has struck an optimistic tone. Just last night, he ticked off the names of six Republican presidential candidates who are backing the initiative: Sen. Ted Cruz (Tex.), Sen. Lindsey Graham (S.C.), former Texas governor Rick Perry, Louisiana Gov. Bobby Jindal, Dr. Ben Carson and Donald Trump. And on Tuesday night, O’Reilly ticked off an even more important backer: Senate Majority Leader Mitch McConnell (R-Ky.), who in O’Reilly’s words has “indicated he will get behind Kate’s Law.”

Oh yeah?

The Erik Wemple Blog asked McConnell’s office about his stance on the proposal. A spokesman replied by turning our attention to a comment that McConnell had made on the July 12 edition of “Fox News Sunday”:

BRET BAIER: A couple more things. In the wake of all the attention of sanctuary cities, after this murder of 32-year-old Kate Steinle in San Francisco, authorities say, at the hands of an illegal immigrant, five-time deportee — will Congress move on sanctuary city legislation?

MCCONNELL: We should. I think any sanctuary city — for your viewers, that means that these are places where they choose to ignore the law — should not be receiving federal criminal assistance money, period.

That response, of course, doesn’t address criminal sanctions against deportees who attempt to re-enter the United States. So we asked McConnell & Co. whether the leader said anything specific about “Kate’s Law.” “He wasn’t asked about that,” responded the spokesman, Don Stewart. When we asked point-blank whether McConnell had given an indication of his endorsement of O’Reilly’s proposal, Stewart replied, “As I noted, we only have the one quote below which I sent to you. He spoke about denying federal law enforcement funding to municipalities that refuse to follow federal law.”

We sought comment from O’Reilly on the substantiation for his McConnell claim. No comment.