Even a smaller group of armed patriots gathered openly would cause hesitation because of the unpopular toll that it would take defeating them. Liberals for the most part wouldn't accept any action any more than Conservatives, and Obama doesn't control a giant robotic force that can't refuse orders.
One of the rumored executive orders Obama will issue will withhold state funds if not obeyed. That's the kind of issues that should be openly defied, and once they try withholding funds then federal tax collection should be stopped. Our best option is getting them to come to us anyway we can before having to go to them. I think it can be much more successful than an armed march on Washington, or having to make the first move to fight. Each side would rather the other escalate any violence, before reacting with violence. Having a specific enemy, and a preferred outlet to act is wanted, but is something you should assume won't be the case.
Open defiance at the local level of these issues and others like Obamacare also have the most potential for a peaceful outcome. I don't think the feds would fill comfortable escalating the situation. The stronger the patriot force and resolve, the less likely they would underestimate the toll that aggression would cost. I believe we can have a peaceful revolt this way, but we all have to do what we can to get things moving in time if it's going to be possible.
www.OathKeepers.org
The new civil disobedience will start out small.