The humourous factor aside, Trump's move was hardly that outrageous considering the point you mention about the Speaker leaving the country during a shutdown. The Democrats really aren't interested in negotiating any more than he is - and really, is that any surprise? Now that they've gotten to this point, they can hold out until they win in one of two ways - either a humiliating Trump climb-down, or Senate Republicans publicly breaking with Trump. And McConnell seems understandably determined to make it the former, not the latter, because he knows the Trump fanboys hold his party hostage and the adult Republicans can't afford to give them more ammunition.

The polls are clear that the public as a whole is blaming Trump, and rightly, but of course it's also true that Pelosi and the Dems could end this crisis and help the affected people at any time they chose, by giving up something that's pretty insignificant in reality, however big a political symbol it may have become. They are prioritizing their political victory over those people's livelihoods, just like Trump is doing. And of course just like the British government is doing in their own crisis.

Not really sure how this is going to end, but it might take quite a while before we get to that end.