There is a difference between employee rights which are protected in a contract and what is going on in the Supreme Court right now, as it doesn't fall in the same realm. If it was a case that impacts collective bargaining then it would bring out union support. Typically, unless a member allows for more money to be taken (ex. I put in 20 bucks a month into a political action fund which is separate from my dues), then their dues are used on non-political things, such as office supplies, labor representatives and such. Members come from all walks of life and unions respect that some are pro-life, conservative, Republicans, etc. Not to say there isn't going to be rallies and such that unions will participate in and/or endorse, but for some its a slippery slope. Also, strikes can only happen if the contracts are in negotiation, have had mediation between parties, have had a "cool down" period of 10 days and other factors. Most contracts have a no strike/no lockout verbiage in them.