The honest answer, for most people, is “I want it to be a powerful political force on my side.” The idea of kicking the cops out of the labor movement has a delicious appeal at a time when police racism is more visible than ever. The idea of kicking the border patrol agents out of the labor movement for endorsing a racist xenophobe whose values would seem to be in direct contradiction to labor would be fun as hell. But such actions would set a dangerous and counterproductive precedent. If you kick out the cops for protecting bad members, you can be sure that a call to kick out teachers unions for the same thing is right around the corner. If you kick out the border patrol agents for endorsing Trump, you can be sure that the AFL-CIO’s internal Bernie vs. Hillary squabble will soon turn into a call to eject those who don’t toe the official endorsement line. Ultimately, kicking out unions that we dislike politically undermines the one thing that gives the labor movement its strength: unity.
You don’t have to like the members of a police union. You don’t have to like the redneck Border Patrol union members who endorsed Donald Trump. All you have to do is recognize that all of us—you, me, the Bernie partisans, the Hillary partisans, the teachers, the restaurant workers, the liberals, the racists, the fucking cops—have one thing in common: we are members of the working class. By standing together as a labor movement, we make the working class stronger. That in turn makes the world a fairer place. That is what class consciousness means. It doesn’t mean you have to like the people you stand with. It just means that you agree to settle your differences outside the bounds of the labor movement, the purpose of which is to support labor. The racist cop and the city worker waving a sign in a protest march against racist cops have a common enemy in economic inequality and unfairness. Whether we like it or not, purposely shrinking the ranks of labor organizations is counterproductive. (Likewise, police unions behaving so outrageously that they get kicked out of labor organizations is stupid.) We can all work together on something we have in common and then tell one another to go to hell when that work is done.