Trump and the Republican Congress are going to appoint many judges during his term, including Supreme Court judges. That could be Trump's most enduring legacy.
Grow a spine. What do they even stand for these days?
Basically, the standard practice used to be for most cabinet appointments to be easily confirmed with bipartisan support. Obama's appointments saw unprecedented levels of push-back from republicans, but still received significant numbers of republican votes. Democratic opposition to Trump's nominations has been, again, unprecedented.
My opinion: perhaps, given the fact that their votes are purely symbolic anyway, some democrats are choosing to 'pick their battles', and vote yes to the picks they feel are halfway reasonable, saving opposition for the cases where (again, in their opinions) it matters most.
AFAICT it's unclear whether the Republicans would, or even could, do away with the Senate's power to filibuster a Supreme Court nomination over this.
At any rate, everyone on Trump's short list of nominees seems basically no worse than Scalia, so things shouldn't change too dramatically for now.