The more I think about it, the more I feel Zelensky not only didn't screw up, as one would initially assume, he actually played his hand pretty masterfully. Of course it's possible he didn't do it on purpose, but end result is the same.
- Ukraine is done for no matter what, it's just a question of do they get taken over by Russia or divided between Russian and US rule (disregarding if Russia will ever agree or US can ever actually get their share)
- Based on history, he himself personally is done for if US wraps up the project, gets what they want and has no more use for him, whereas if Russia takes over he might actually live, after all Russia could have killed him long ago but didn't.
- His personal survival is also very much tied to support from his deep state backers, who do not like Trump. If he's worried about assassinations it's not Trump he has to placate.
On the other hand, by going to the White House and quite literally disrespecting Trump in his own office, he's called Trump's bluff of cutting military aid. If Trump does so, Trump might try to blame Zelensky, but Zelensky can also blame Trump, more importantly the Deep State will blame Trump. If on the other hand, and in I think the most likely scenario Trump does not cut aid, Zelensky would have just demonstrated Trump has no cards, Ukraine might take longer to collapse, but Zelensky himself becomes even more important to his European backers.
It might look initially like Zelensky screwed up yesterday, but deliberately or accidentally, Trump was actually the one who screwed up, his choices are now reduced to either cutting aid and take full blame for Ukraine's collapse, or not cutting aid and effectively getting humiliated in his own office.