The demographic changes coming over the next few decades — the continuing rise of a more diverse electorate, with more liberal views than previous generations — won’t destroy the Republican Party or make it electorally insolvent. But it may make right-wing conservatism a rump ideology, backed primarily by a declining minority of older rural and exurban white voters. You can already see this taking shape. Among the youngest Republicans, 52 percent say the government should be “doing more” to solve problems, as opposed to 23 percent of Republican baby boomers.

In this environment, the only way to preserve right-wing conservatism in American government is to rig the system against this new electorate. You tilt the field in favor of constituencies that still back traditional Republican conservatism in order to build a foundation for durable minority rule by those groups. In just the last week, we’ve gotten a glimpse of what this rigging looks like in practice.

Let’s start with the census dispute that’s now before the Supreme Court. The Trump administration wants to add a citizenship question to the 2020 census, asking Americans to declare their status in order to participate. The government asks a similar question in the American Community Survey, a more frequently performed survey that is given to a sampling of households. But it hasn’t asked all households the citizenship question on a decennial census since 1950. Wilbur Ross, the secretary of commerce, whose department oversees the Census Bureau, wants to bring it back. He has the authority to do so. The problem is that he circumvented the official process. The case before the Supreme Court deals with whether the question can stand, given Mr. Ross’s decision to, as a federal judge put it, upend the rules that govern adding a question to the census.

The citizenship question is likely to make the census less accurate, to put it mildly. In the face of the harsh anti-immigrant policies sponsored by the Trump administration, as well as uncertainty about their own status, immigrants may not want to reveal their legal status to the government.