They were elected by Republicans. I'd not want to face the angry Trump voters if they failed to do their duty.
Earlier today, saw on one of the election websites, don't remember which one, a county map of Pennsylvania marked blue or red for each county. Only the two counties that contain Philadelphia and Pittsburgh (and maybe 3 or 4 other counties) were blue, and ALL the rest of the large number of counties in that state were Trump country (red counties)! I had no idea ... amazing!
Very similar to total US map. Big cities trend freebies Dem.
California and NY give Dems a big head start Re presidential election
Electoral college was set up try to balance all citizens