What is one of the first thing you think of when you think of unions? They're organized. For better or for worse, they are VERY organized.
Case in point, they have local meetings at least every 2 months. Most locals have them once a month. Also, they have committees for just about everything. Veteran, women, civil rights, educational, recreational and others, depending on the local.
The unions also have educational getaways that are paid by union dues. Each union has a different place, owned by the union. For the week or weekend that you are there, the worker will go to workshops. They'll learn different ways to strengthen the union. Teach them every thing they to know, so when they go back to work they're armed with knowledge.
This is how the union is able to mobilize the way they do. They are highly organized. If there is a political protest that the union wants you at, they have what is referred to as a 'call out'. The union pays you for the time you would have been at work to show up. Sometimes they even provide transportation. All this is paid for by union dues.
So the question is, how do we as conservatives rally against this?