WASHINGTON -- There is much blame to go around in this government shutdown, but if one person deserves more culpability than all others, that person is Matt Bevin.

     Bevin isn't a member of Congress or an administration official. He lives in Louisville and runs a family business that makes bells. But he has played a pivotal role in the shutdown by sidelining Mitch McConnell, the Senate Republican leader and the man best positioned to negotiate a solution to a political crisis that threatens to upend the American economy.



     McConnell is as conservative as they come and a bitter foe of President Obama, famously declaring that his top goal was to make Obama a one-term president. The Kentuckian gives over-the-top daily speeches on the Senate floor denouncing the president and Democrats in the harshest terms.



     At the same time, McConnell has brokered compromises in the past when the country faced economic calamity. He struck a deal with Vice President Joe Biden in the early hours of 2013 to save the nation from going over the so-called fiscal cliff. A year and a half earlier, the same duo negotiated a compromise to avoid a default on the national debt.



     This time around, McConnell is unable to cut a deal. And that's because of Bevin, who has launched a tea-party-backed challenge to McConnell in the Kentucky Republican primary.



     Bevin has the backing of conservative groups such as the Madison Project, which propelled Ted Cruz to victory in the Texas Republican Senate primary. And the Madison Project doesn't take kindly to dealmaking. "Mitch McConnell emblematizes the rudderless leadership, vacuous core, and duplicitous tendencies of the powers that be within the party," the group wrote in endorsing Bevin. "He isn't just part of the problem. He is the problem in Washington, D.C. In fact, as we write this endorsement, he is pressuring senators not to join the effort to defund Obamacare."



     Indeed, it appeared at first that McConnell was prepared to play the dealmaker again. He opposed Cruz's scheme to fight Obamacare by blocking legislation to fund the government. Hours before the shutdown began at midnight Monday, McConnell floated a plan to keep the government running for another week.



     Bevin howled. "Where was Mitch McConnell while Ted Cruz was standing and fighting? Well, he was sleeping. Literally," Bevin wrote on the conservative website redstate.com. "And when he wasn't sleeping, he was whipping his fellow Republicans to vote against Sen. Cruz's effort."



     Bevin's conservative patrons joined the assault. The Madison Project complained about McConnell's "habit of parachuting in." The Senate Conservatives Fund charged that McConnell had "surrendered to Barack Obama, Harry Reid and the Democrats."



     McConnell abandoned his dealmaking. After a meeting with Obama at the White House Wednesday, he went on CNBC and declared the session "unproductive," the Democrats "unreasonable" and the president's position "unacceptable." By Thursday, he was serving as a mouthpiece for Cruz on the Senate floor, taking ownership of the strategy Cruz had devised and defending Cruz when the Texas freshman was criticized by Reid, the majority leader.



     McConnell is the most visible manifestation of the problem, but his dilemma is key to understanding why this shutdown wasn't averted and why there is little movement to end it. There are relatively few die-hard conservative ideologues in Congress. But the rest of the Republicans are terrified of being knocked out in a primary by a true believer. So they are acting like tea party conservatives. Were there a secret ballot, Republicans would vote overwhelmingly to keep the government open rather than seek to force Obama to surrender the main achievement of his presidency -- something no president would do. But there is no secret ballot, and McConnell, like House Speaker John Boehner, must choose between the good of the country and keeping their jobs. So far, they've chosen the latter.

     The terror of the tea party isn't necessarily rational. Polls show McConnell trouncing Bevin. And yet, he panics. As top Republican on the appropriations subcommittee for foreign operations, McConnell spent years funneling billions of dollars to Egypt. But this year he joined tea party darling Rand Paul, also from Kentucky, in voting to eliminate aid to Egypt. A longtime hawk, McConnell also sided with Paul and Cruz in opposing military action in Syria -- after Bevin and Kentucky tea party groups applied pressure.

     Now the stakes are much higher: closure of the federal government and a default on the national debt. And the man who could rescue us from all this is being marginalized by a small businessman with a big mouth.