They are not acting out of cowardice. It is a concept that author Micheal Prell calls "Underdogma".
They support the tiny Muslim minority precisely because they are a tiny minority. They're convinced that a minority, an "underdog", has virtue simply because it is in the minority.
Conversely, America is the top dog. The top dog is evil, simply because it is the top dog. Nobody (except them) gets to be top dog out of merit, it is always by cheating and evil. As part of this tog dog group, liberals exhibit a tremendous amount of self-hate.
They believe that everyone should be on the same level and that everything should be "fair". Of course, the top dog has had it so good for so long, he needs to suffer for a time at the hands of the newly elevated underdog. How long does the top dog need to suffer? Nobody has figured that out yet. They'll let everyone know when the time is right.
I’ve never seen that ‘liberals are cowards’ play out in the streets, either. They push until they get what they want.
Republicans on the other hand, well this line had no problem being understood when used back in 1970.