WASHINGTON — A more conservative Supreme Court appears unwilling to do what Republicans have long desired: kill off the Affordable Care Act, including its key protections for pre-existing health conditions and subsidized insurance premiums that affect tens of millions of Americans. Meeting remotely a week after the election and in the midst of a pandemic that has closed their majestic courtroom, the justices on Tuesday took on the latest Republican challenge to the Obama-era health care law, with three appointees of …