The Export-Import Bank went into liquidation a month ago when its congressional authorization lapsed. Opponents of corporate welfare from both ends of the ideological spectrum have long agreed that this is desirable, and no further action is needed in Congress to make sure the bank slips into oblivion.

Senate Majority Leader Mitch McConnell, R-Ky., says he agrees with those who want the bank to go away. This week, he threw it a lifeline, allowing two votes in which the Senate overwhelmingly supported bringing Ex-Im back to life. As McConnell put it, "I don't see any reason they should not be able to debate and then vote on this to sort it all out."

This is understandable, it reflects the openness with which McConnell promised to run the Senate when he took over as its leader.

But at first, McConnell went further than that. He used a parliamentary tactic against the bank's opponents, temporarily blocking their attempts to amend the bill in response.

These conservatives' amendments, which focused on Planned Parenthood and the nuclear deal with Iran, were intended to raise the political price of restoring the Ex-Im bank — high enough, in theory, that Democrats might become unwilling to pay it. Even if the amendments failed to pass, they would at least force Democrats to go on the record voting to keep federal funds flowing to an organization that harvests human body parts for the biotech industry and to support President Obama's lifting of sanctions against Iran.

It's true that these amendments were not relevant to the underlying bill. But the vote on the bank wasn't relevant to it either. It was actually attached to a six-year highway reauthorization bill. It was not the conservatives who opened to the Pandora's Box of irrelevant amendments. They were seeking to do only what McConnell had permitted others to do.

McConnell promised to preside over a functional Senate, unlike his predecessor. For the most part, he has kept that promise. Until earlier this week, he had eschewed Harry Reid's tactic of blocking other senators' amendments by using his special prerogatives as majority leader. It was disappointing to see him apply a heavy parliamentary hand, just in time to block conservatives who saw a real chance of victory.

If Ex-Im is ultimately resurrected because Republican leaders deprive conservative lawmakers of the parliamentary tools available to their peers, the damage could be irreparable. The trust between conservatives and the Republican Party leadership will be broken. The intra-party Republican war of 2013 will be back in force. And it will be easy to understand why conservative voters and activists get so upset — and even display a willingness to support ruinous, belligerent, wild-card candidates like Donald Trump.

House leaders announced on Monday that they will not stay in town to consider the Senate's six-year highway bill before leaving for the August recess. That means Ex-Im stays dead, at least for now, no matter what the Senate does.

Also late Monday night, McConnell turned back from the disastrous course of stifling conservatives. He opened the door to another measure, sponsored by Sen. Mike Lee, R-Utah, that will force President Obama to veto the repeal of Obamacare, separate from the highway bill. This is the kind of cooperation the Senate needs to work, and it is a critical step toward maintaining the trust of the base and keeping Republicans working together.