Faithless electors have occurred in American presidential election history but never to alter the constitutionally elected outcome. Those kinds of blatant shenanigans will not be acceptable to cooler heads in either party.
Unfortunately, the electors are in no way obligated mirror the popular vote. This is by design, as the Framers knew that the vast majority of people, then as now, are largely ignorant of the political process and largely uninformed. It has happened before that the electors voted contrary to the popular vote, as is their prerogative.