52% of Californians voted for Prop 8 in 2008. But: Had you asked 10, 25, 50, 100 years before that, what would the outcome have been? Draw a graph along that line through 2008 and you can track the development of public opinion.
You're basically making the "be on the right side of history" argument, but you presume to much. For example public opinion on abortion has been roughly flat for fifty years.
Maybe in the US, but internationally is another matter entirely.
Also: I'm not agreeing with your wording of "blacklisting people for political views". I do, however, think that the higher your potential impact on society, the higher the scrutiny towards the outlier nature of some of your opinions should be.
In other words: The further up an employee in a company or a politician in the respective political field moves on their ladder, the more is it justified to hold them closer to the standard set by median public opinion on certain matters.