WASHINGTON—In a stunning disclosure this week, congressional sources revealed that the acrimonious gridlock in the U.S. Senate traces its origins to a single November evening in 1986, when Sen. Harry Reid (D-NV) engaged in sexual intercourse with Sen. Mitch McConnell's (R-KY) then-wife, Sherrill.

"The impenetrable stalemate on crucial issues is not due to a widening ideological divide between parties, as we once thought," said Brookings Institution senior fellow Sarah Binder. "Rather, this inability to move the legislative process forward stems almost exclusively from a jealous and resentful Mitch McConnell, who has been unable to erase the mental image of Harry Reid pleasuring his wife one wild, passionate night some 25 years ago."

"It's been the elephant in the room for decades, and frankly, neither senator is willing to just man up and bury the hatchet," Binder added. "Unfortunately, our democracy continues to suffer the consequences."

Congressional insiders, who confirmed they were glad to finally have all the tension out in the open, said the rift began when the newly elected Reid met McConnell's wife at a Capitol Hill cocktail party shortly after the 1986 midterms, an encounter that eventually led the pair to a rented room at the Watergate Hotel for an intimate midnight rendezvous.

Neither senator will admit that recent battles over extending the Bush-era tax cuts directly stemmed from the time Reid gave Sherrill a back rub in the congressional cafeteria.

In the aftermath of that fateful night, a feud was born that would soon lead to hundreds of famously spiteful battles over everything from immigration reform measures, to the 1987 Supreme Court nomination of Robert Bork, to at least 14 different energy bills, sources within both parties said this week.

"Look, something was bound to happen that night between them—Sherrill was a shy and attractive conservative, and Harry was this dashing, bad-boy former gaming commissioner from Nevada," said a longtime Republican aide who attended the 1986 Senate function and spoke on condition of anonymity. "I mean, what do you expect? Frankly, Mitch should have known better than to let Sherrill out of his sight in the first place. Harry was a real wolf back then."

"Of course, Mitch actually didn't find out until months later," continued the aide, who claimed that McConnell overheard Sens. Joe Biden and Ted Kennedy exchanging graphic details of the liaison in the Senate men's room. "But when he did he totally flipped. Next thing you know, he's angrily drafting some spiteful legislation to store all of the country's nuclear waste at Yucca Mountain in Harry's home state."

According to the Congressional Record, the senators' dispute has only escalated over the past quarter century. As the two men moved up the ranks of their parties, Reid blocked scores of Social Security reform efforts, tax-cut proposals, and veterans' health care bills that were sponsored by McConnell, while in 12 successive Congresses, McConnell introduced a defense-of-marriage amendment aimed specifically at prohibiting adultery.

Sources stated that the rival senators both voted to authorize Operation Desert Storm in 1991 for the sole purpose of asserting their masculinity in front of each other, unwittingly causing the resolution to pass with a narrow 52-vote majority.

Additionally, records show that McConnell filibustered campaign finance reform bills on nearly two dozen occasions, using his hours at the Senate lectern to make a number of indirect, off-color remarks about Reid's wife, Landra, and to claim confidently that he was in the best physical shape of his life.

"Much like Harry, Mitch has always strongly believed that campaign finance reform is of the utmost importance in modern American politics," the Republican aide said. "But he's been going against his own principles to fight these efforts tooth and nail ever since he heard a rumor that Harry was well hung."

"People try to tell Mitch, 'Hey, get over it, man, whatever happened was years ago and you're both different people now,' " the aide continued. "But he just can't let it go. Doesn't even seem to want to let it go, in fact."

Sources reported that the senators appeared to overcome their feud for a brief period in 1996, after McConnell had divorced his first wife and remarried. Although the two worked together to pass welfare reform that summer, their truce reportedly came to a spectacular end at the annual Senate Christmas party, when McConnell claimed he saw Reid making eyes at his new wife, Elaine, and, according to one party attendee, "went completely ballistic," excoriating Reid in front of the entire 104th Congress, and subsequently donating $1.5 million of his own money to establish an anti-Reid PAC.

"This whole thing could have been settled years ago if Harry had just apologized for sleeping with Sherrill and let Mitch sock him in the face so they could both get it out of their systems," said a senator who asked not to be named, claiming that the 25-year-long congressional debacle had gotten "pretty silly." "They're like little kids, honestly. Both of them. Does anybody even still remember what happened that weekend besides them?"

"I guess things could be a lot worse, though," the senator added. "Thank God Mitch doesn't know about Durbin, Schumer, or McCain."