The new Republican Congress may not be able to repeal and replace Obamacare entirely, but it could make substantial progress by targeting the health law’s key structural components.

This November’s electoral wave reopened and widened the strategic playing field for critics of the Affordable Care Act (ACA). Republican control of both houses of Congress, plus larger majorities of state governors and state legislatures present both opportunities and challenges to move beyond rhetorical opposition and advance changes in national health policy. Initial speculation tends to focus more on tactical considerations on Capitol Hill: which items are easiest to pass in the Senate, how to use budget reconciliation, and which votes will “look good” politically even if vetoed by President Obama.

By Megan McArdle: While I was away last week, Vermont decided to scuttle its single-payer health-care plans. I predicted as much six months ago, for one simple reason: A single-payer system would cost too much. When faced with the choice of imposing double-digit payroll taxes or dropping his cherished single-payer plan, the governor of Vermont blinked.

“But Megan!” I hear you cry. “Single-payer systems are cheaper, not more expensive! Look at Europe!”