If the federal government clearly isn't following the Constitution a case can be made for rebellion against its tyranny. I suppose that could be done nationally or by a state.
But if you have the vote and representatives in Congress and aren't being physically oppressed by the government, it's hard to make the case for rebellion stick.
In other words, the government would have to be truly repressive and tyrannical. It can't just be that somebody thinks that the Federal Reserve is unconstitutional.
If things go downhill, civil disobedience is probably a better place to start than threats of revolution or secession.
Before it comes down to tyranny and rebellion, there may be an attempt to dissolve the union.
I wouldn't want to see that happen, but if it's done at the federal level through Congress or a national convention it would have the legitimacy that unilateral state action wouldn't have.
We are watching before our very eyes the governments of many Western nations importing a new constituency, one that has no attachment to our historic civilization and (in the case of America) no particular fondness for the Constitution. This is being done by political elites who want unlimited power and who regard our traditional faiths and institutions as being passe relics that belong in the dustbins on history. They don't plan to kill us or imprison us, but to tax the hell out of us and use us as a Goldstein-like foil (as in 1984) to keep the non-white, feminist, homosexual, leftist, and other post-60s groups whipped into a constant hatred against us and our allegedly repressive institutions such as traditional marriage and the family.
Thus, at some point in the future, we'll be in a society where we're taxed like hell to support the 60% or so that keep the government in power, and are constantly (and I mean 24/7) berated by government, the educational establishment, the media and other outlets. We'll be constantly on the defensive as the government finds new "discrimination" on our part that needs redress. Reparations to feminist groups for not giving women the vote 800 years ago. New laws banning Bibles from hotel rooms since homophobic hate literature has no place in a business involved in interstate commerce and public accommodations. There will never be an end, as I've said before, because liberalism itself never ends. It exists to destroy that which sustains our civilization.
This is clearly already starting. So Gov. Perry is right, we may need at some point to peacefully withdraw and go our own way in the few remaining states that are pockets of free America as it once was.