With his usual eloquence Will clarifies the difference between actual conservatism (I call this true liberalism) and various brands of populism masquerading as conservatism. It’s not about the type of government or who wields the power of government. It’s about the role of government:

Liberty

“Judicial review — let us be candid: judicial supervision of democracy — troubles people who believe, mistakenly, that the Constitution’s primary purpose is simply to provide the institutional architecture for democracy. Such people believe that having government by popular sovereignty is generally much more important than what government does; hence courts should be broadly deferential to preferences expressed democratically. This is the doctrine of those conservatives who deplore, often with more vigor than precision, “judicial activism.”

More truly conservative conservatives take their bearings from the proposition that government’s primary purpose is not to organize the fulfillment of majority preferences but to protect pre-existing rights of the individual — basically, liberty. These conservatives favor judicial activism understood as unflinching performance of the courts’ role in that protection.

That role includes disapproving congressional encroachments on liberty that are not exercises of enumerated powers. This obligatory engagement with the Constitution’s text and logic supersedes any obligation to be deferential toward the actions of government merely because they reflect popular sovereignty.

The latter kind of conservatives are more truly conservative than the former kind because they have stronger principles for resisting the conscription of individuals, at a cost of diminished liberty, into government’s collective projects. So a constitutional challenge to the mandate serves two purposes: It defies a pernicious idea and clarifies conservatism.”