Traditional conservatism would have recognized the danger in politics creeping further onto what was once the terrain of the social sector. One of Alexis de Tocqueville’s most famous insights was that civil associations, which he described as “in no way political,” enlivened American life and, crucially, preserved freedom from an all-embracing state. Joseph Schumpeter, the Austrian political economist, predicted that one factor undermining capitalism would be “wars of conquest” on the private sphere “by the men of the public sphere.” The conservative sociologist Robert Nisbet saw the erosion of these buffers as conducive to tyrannical politics. He observed that the individual had a need for community and would seek it in the state if it was unavailable in the society.

Mr. Trump is both an accelerant and a reflection of this longstanding erosion of the civic spaces that mediate between individuals and the state. This is a central irony of Trumpism. It drew part of its force in 2016 from a sense of economic and social dislocation from these spaces. Yet Mr. Trump has been less interested in restoring them than in offering his personality as a substitute.

In this sense, not only is there no separation between the political and the private, but there is also no separation between Mr. Trump and the presidential office — something his copious use of the first-person singular indicates.

In this, Democrats are not innocent. They, too, have fueled presidential celebrity. It is difficult to conjure a modern occupant of the office who has not. Before he won the office in 1912, Woodrow Wilson theorized about the need for presidential celebrity and then attempted to embody it. He wasn’t the last.

But Mr. Trump occupies the office now, and the conservatism he professes places special importance on limiting the scope of the political. Instead, his personality-driven politics requires attacks on anything, whether public or private, that obstructs an unmediated path from his voice to his followers’ ears.

This is both the result of the erosion of social institutions that Mr. Trump rued in 2016 and the cause of its acceleration. Its end point, if Mr. Trump’s proponents and critics alike do not stop filtering every issue through him personally, will be a politics that reaches everywhere even as citizens feel increasingly alienated from it.

Greg Weiner (@GregWeiner1) is a political scientist at Assumption College and the author of “Madison’s Metronome” and “American Burke: The Uncommon Liberalism of Daniel Patrick Moynihan.”

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