Trans People and Civil Rights

An actual argument I have seen persist among Evangelicals and Trump supporters is this one: Trans people are only .01% of the population (or .03% or whatever number they've been given by Fox News that morning), so why should the rest of us have to accommodate them?

It's an argument I can't believe anyone thinks is legitimate, but let's say you do.

What percentage of the population does a given group have to reach before you'll agree they should have civil rights? The deaf are only .38% of the population. Jews are less than 1%. Filipinos are less than 2%. Do we strip away their civil rights as well?

The USA doesn't base civil rights on how big a group is. Or at least we didn't used to do so.