Will Wilkinson objects to Democrats referring to Republican debt ceiling tactics as terrorism:

The political tactics that seems to each of us most dangerous and irresponsible inevitably reflect deeper assumptions about the way economies and governments do and ought to work. Of course, not every set of assumptions about market and state are equally reasonable. But we should not be too hasty to ascribe criminal, enemy-of-the-state status to those who see things differently.

His colleague Matt Steinglass points out that Mitch McConnell himself compared the tactic to hostage-taking, and proceeds to argue:

There is some interesting thinking to be done on how a hostage that isn't worth shooting can possibly be a hostage that's worth ransoming. I think it comes down to social conventions and where they place the burden of expectation. Any hostage-taker always tries to create a system of expectations in which the party asked to pay the ransom is responsible for whatever happens. Forcing Democrats to pay the ransom once helps to institutionalise this expectation. After all, how could Republicans be expected to know that Democrats wouldn't pay the ransom a second time? But everyone should then understand why many Democrats now feel that the first order of business, before anything else can be done, is to dispel the impression that you can hold the American economy to ransom for whatever political priority you may deem most important, and Democrats will eventually cave. Democrats will not be able to achieve any of their priorities until they re-establish the understanding that when Republicans make threats, they, not Democrats, are responsible if the threats are carried out.

That's a great point. I also think that Wilkinson is missing the more fundamental distinction here. It's common for parties to vote for legislation that the other party thinks will have horrific effects. Democrats think the Paul Ryan budget would lead to mass suffering. Republicans said the same about the 1993 Clinton tax hikes. We should learn to accept the fact, as Wilkinson says, that parties will advance policies with strongly different assumptions about the market and the state.

The difference is that the Republicans this time threatened to carry out a policy that they themselves believed would have horrific effects. I can't think of any precedent for that in national politics. It's also behavior that seems to differ in degree but not in kind from actual hostage taking. A hostage taker does not want to murder an innocent person, but he is willing to risk that outcome, and seeks to leverage his willingness to risk that outcome in order to obtain concessions. Now, one distinction is that your typical hostage taker wants money, whereas the Republicans wanted policy concessions that, as Wilkinson notes, they genuinely believe will improve the world.

But what about politically motivated hostage takers? They exist, too. Is there any important moral difference between threatening to kill somebody in order to achieve a policy goal and threatening to deliberately unleash global economic chaos in order to achieve a policy goal? I can't see any.