his is why it’s so remarkable that our constitutional order has lasted so long, given the perpetual incentive — common to both parties, and all three branches of government — to abandon its safeguards in order to push a particular agenda....I guess Douthat was trying to end on a poetic note? To throw in a few more slams at Obama, an implied comparison to Jimmy Carter, a dismissal of concerns about Republican obstructionism and the stated goal of certain Republican leaders to put the defeat of Obama ahead of the welfare of the nation?
[The notion of a president tied down by an antiquated system of government] suggests the possibility that some of the ways this president has been baffled, legislatively and perhaps soon in the courts, reflect the genius of our constitutional system rather than its failings. It’s a system that often lacks principled defenders, but that’s designed to defend itself.
But at heart, Douthat's point is banal. He's simply observing that Congress exists.
Douthat appears to believe that the problem is something more than a congressional dereliction of duties, but any such belief is undermined by his own example of the Guantánamo detention center. That prison is kept open not by the wishes of the President but by an act of Congress. If Congress objects to "almost the entire Bush-era wartime architecture [that] has endured", it can pass a law imposing limits on that power, appropriate checks and balances, judicial review... If Congress objects to an executive order affecting the enforcement of immigration laws, it can pass a law that removes that discretion or that resolves the issues that the President is attempting to address by executive order. There's no mystical emanation from the Constitution that allows it to defend itself - it's the fact that should it choose, Congress can end its dereliction of duties and pass legislation.
No question about it, Presidents are happy to assume the powers that Congress grants to them, whether by action or inaction. No question about it, despite the chest thumping and alligator tears, Congress often prefers that the President act unilaterally on contentious issues such that its members don't have to take a stand or explain their votes to unhappy constituents. The cure for that is for Congress to do its job.