In his book Keeping the Republic, Mitch Daniels relays an event from his tenure as Indiana governor that illustrates a wider political reality.

Governor Daniels set out to reduce Indiana’s property taxes and spent weeks examining all the options, including abolishing property taxation completely. But according to Daniels, “In order to wipe out local property taxes totally, we would have had to more than double the state sales tax, or double the state income tax, or some equally onerous combination of the two.” The costs of complete abolition of property taxes “would have crushed our state’s rapidly improving status as an attractive place to invest and create jobs,” Daniels writes.

No matter. A well-organized, anti-tax citizens’ group, Let Us Vote, demanded total elimination of the tax. The Daniels administration showed them the mathematical impracticality of their approach and the flawed assumptions they were embracing. The Daniels plan slashed property taxes by more than one-third, to what would prove to be the lowest level in America. Nevertheless, Let Us Vote became the loudest lobby against the reform.

Daniels eventually prevailed, enacting the largest tax cut in state history. But for a time, according to Daniels, “this signal achievement was endangered by good folks who not only agreed with our low-tax, limited-spending policies, but agreed so strongly that they almost derailed any progress at all.”

What are we to make of this and similar episodes?

For one thing, such clashes are a long-standing feature of political life. During his presidency, even the now-iconic Ronald Reagan was considered a sell-out by some prominent movement conservatives. For example, Richard Viguerie, an influential figure in what was then called the “New Right,” was a persistent critic of Reagan, going so far as declaring in 1987, “In other important matters he [Reagan] has changed sides and he is now allied with his former adversaries, the liberals, the Democrats and the Soviets.” That same year Howard Phillips, the founder and chairman of Conservative Caucus, called Reagan “a useful idiot for Soviet propaganda.”

The point here isn’t to make these individuals look silly; it’s merely to point out there are inherent tensions between lawmakers and those who conceive of themselves as defenders of doctrine. One is concerned with governing in a fallen world; the other with fealty to principle. One is satisfied with incremental achievements; the other tends to care more about purity. Both groups need each other — and both would be well-served if they better understood each other. I say that because many politicians are tempted to compromise on principle, to reach a deal for its own sake. For them, outside pressure is useful to apply. On the other hand, some conservatives believe that compromise is in principle wrong, an outlook that is contrary to the views of the founders and the intent of the Constitution (a document that was itself the product of compromise).

This doesn’t mean we shouldn’t air our differences. And no one should be above criticism. But as a general matter it might be helpful for those who are eager to berate public officials for being unprincipled to serve in high positions in government (and if they have done so, to recall the experience). They might develop a bit more sympathy for those who have to make tough judgment calls on what constitutes a reasonable compromise versus  a capitulation. It’s far easier to sit in front of a camera, behind a microphone, or over a keyboard dispensing advice than it is to successfully govern in the real world. I’ve served under three presidents and been a commentator on current events, so I know of what I speak. The problems of the nation and the world seem much easier to solve from my current perch.

It’s of course perfectly legitimate to conclude that a politician who opposes a deeply held principle of an individual forfeits that person’s support. But today there’s more pressure than I can ever recall to insist those in public life check this box and take that pledge or else their conservative bona fides are called into question. So when he was considering a run for president, Governor Daniels was attacked by some on the right as a RINO (Republican in Name Only) despite the fact that he is arguably the finest governor in America and a man of impressive conservative accomplishments. This doesn’t mean one can’t disagree with Daniels or anyone else; but it does mean those who insist someone like Daniels should be “disqualified” from consideration and that his views are “beyond the pale” (as some leading conservative activists said) would reduce conservatism to a rump movement if they had their way.

One of the signs of a healthy, self-confident political movement is intellectual vitality, a wariness of ideology and enforced orthodoxy, and an openness to different approaches to solving urgent issues. At the core of conservatism, after all, is a certain humility rooted in a view of human nature. Conservatism begins from the proposition that even the brightest among us has an imperfect understanding of things, that we can only know in part, that for now we see through a glass darkly. It believes politics is difficult because human beings (and life) are complicated. Sometimes the world doesn’t behave, and events don’t unfold, as theories predict. At its best, then, conservatism is open to new evidence, to adjustment and refinement, to self-examination and reflection — not as an excuse for avoiding embracing truth but as a means to better apprehend it.