There are more than 300 million people in America. Since the 70's, America has been pretty starkly divided into two camps. Liberals like me dislike the Republicans—the audience of Fox News—probably as much as you do.
You are correct. The Republicans are still around. But the demographics look optimistic—young people and minorities are much more often Democrats, which does not speak well for the Republicans. They are a powerful shrinking minority.
In any case, it certainly doesn't make sense to judge all 300 million Americans based only on the 50 million idiot hardcore Republican who are Fox News' audience.