Robina,
First amendment protects your free speech from infringement by the government. It doesn't protect you from socioeconomic consequences of the same.
He can't be arrested and prosecuted for what says. But he sure as hell can be booed and even booted out of a job for it. Google, a private institution, is not obligated to provide him a platform for his views by the first amendment.
In America, the latitude for a boss to fire you is almost limitless. This guy stands no chance in court.