In this instance the fatalism is a result of almost-literal helplessness.

- they can pretty easily cram someone thru before the election
- if they decide not to, that only makes them look "good" to moderates, which could possibly galvanize voters in their favor and swing some important Senate races in their favor, as well as possibly the prez election
- the election has a high likelihood of being contested, especially if Trump loses. Now any election case goes to a 5-3 conservative court
- even if all goes right in November, we're counting on proven pieces of shit like Collins and Murkowski to keep their word and not vote for Cruz or Cotton during the lameduck period

Again I get what you're saying, but this situation is pretty hopeless if repugs decide to do repug things. And even if they kinda don't.