The United States Government consists of three branches: an Executive, headed by the President; a Legislative, comprising the House of Representatives and the Senate; and a Judicial, of which the Supreme Court is the final arbiter. At the time of this writing, the Republican party controls all three branches, including majorities in both chambers of Congress. Congress is responsible for passing laws on funding and has the power of the purse. As a result, shutdowns need to resolved by Congress.

Blaming Democrats for the shutdown makes little sense. For Democrats to be responsible, they would need to control, at a bare minimum, one of the two chambers of Congress. They do not: Republicans control 53 out of 100 Senate seats, and 219 of 435 House seats. This is more than half of each chamber.

There is a counterargument that the Senate, despite having a Republican majority, nevertheless has a history of requiring 60 votes for some bills. This is accurate, but both parties have have removed that rule when it suited them. Most recently, the GOP changed rules to confirm 48 nominees in a single vote.^[1] If Republicans wanted to stop the shutdown, they could trivially do so by changing the rules of the chamber. They have not.

If you feel a need to blame a party, go ahead. I would however suggest blaming the party in charge, which is, again, currently the Republicans.