GEICO has a perfect right to hire and fire whomever they please. They want to sell insurance to moonbats and rightwingers and everyone else. They do not chose to appeal to a niche market. If one of their more prominent spokesmen appears to be criticizing a figure who is sacrosanct to about 30% of their potential customers, they should be expected to fire him.
You have a right to your opinions. You do not have a right to a job.
And Conservatives have a perfect right to buy insurance from somebody else, and let them know why. Let the wars begin, and may the righteous side win.