"Seems to me that the courts standing up to Trump have given the legislators and other institutions the spine they need to stand up to him on other issues"

That would be a bit of a stretch. Legislators are concerned with one thing only - reelection. Current Health Care legislation may be DOA in the Senate, but they will write their own version and is far from a dead issue. The job of the court is to interpret, not rally the troops. If the SCOTUS sided with Trump's ban would they be considered as not "standing up" to him?