If they passed the bill in the senate as-is, and Obama signed it, he could easily just keep spending the money. By the time anybody could even start the process of using the courts to stop him, December 15th would roll around, and the entire thing would be moot. No court would rule that anybody had to give any money back.
It seems unfortunate that there does not appear to be something like a ‘vote of non-confidence’ in the US legislative system.
That said, Cameron didn’t call for a vote of ‘confidence’ when he wanted the UK to go to war in Syria and lost. THAT shoud have been a vote of ‘confidence’ in their government.
There are good and bad aspects to each type of government. There will always be politicians who ‘play’ the system to their advantage, like 0.00.