Americans’ trust in government institutions has plummeted over recent decades. We have experienced huge declines in confidence across the board, including for Congress, the presidency, the Supreme Court, even the Defense Department and the Food and Drug Administration .

We have also seen huge cleavages by party, with Republicans having substantially less faith than Democrats that government can be trusted to do the right (or even merely competent) thing. On almost every core function of government — such as strengthening the economy or keeping the country safe — Republicans evaluate the public sector’s performance more negatively than Democrats do, according to Pew Research Center polling.

After watching the Republican National Committee’s convention this week, I think I’ve figured out what’s going on.

The problem is that Americans — and conservatives in particular — claim to want small, stingily funded government. But they’re making bigger (and more expensive, and less legally achievable) demands about what government should be responsible for.

This cognitive dissonance inevitably leads to disillusionment.