It's not a close call. It's not easy, but it's not a close call. The argument against a shutdown is that Dems don't really have any leverage anyway and letting the government shut down means Trump/Elon/Vought can choose to shut down whatever they want. But they're already doing that. Courts will continue to function but DOJ staff will be greatly reduced, and hobbling the DOJ's ability to defend Trump is a good thing, not a bad thing.
The argument for a shutdown is that Trump is weaker right now than he will be in six months if they let this CR pass. He's shocked a lot of people who still remember when things were actually pretty good just a couple of months ago and he's galvanized a furious opposition again. If Dems cave on this CR that opposition will splinter and another six months of Trump's insanity will cause a lot of people to just go numb and tune it all out. Besides, he and Elon and Vought have been shutting the government down for nearly two months already. Passing this CR will effectively ratify their crimes and essentially cede Article 1 powers to Trump. It will render Congress a rump institution. Better for Congress to just shut down and not operate and not fund anything for the next 3.5 years than that. That's not even getting into how the bill defunds DC's cops, probably so they can replace them with some ICE shitheads who will arrest any troublemaking protesters.
And they don't really want a shutdown. Elon may sort of think he does occasionally, but he's a fucking idiot. If there's a shutdown Trump and the GOP will get the majority of the blame because the shit they're doing right now is wildly unpopular and people want it to stop. There's a reason the GOP unified to pass this fucking thing and it's not any 4d chess shit. Trump can't even fucking play checkers, much less chess, and is already talking about supporting a primary challenge against their lone holdout. He doesn't want a shutdown. These guys are fucking bullies, which means they're cowards. There's nothing a coward is more afraid of than someone fighting back.