The inflation of presidential power over the last century would mystify James Madison. He predicted that the people would be more loyal to legislators than to the executive and that Congress would jealously protect its power. Yet Congress has repeatedly ceded its authority in recent decades, and Americans, who have become more intensely partisan, increasingly form political identities based on their loyalty or opposition to the president.

President Trump’s order for an extravagant parade showcasing American strength — which the House recently endorsed in its version of the National Defense Authorization Act but which the Senate Armed Services Committee did not — suggests one explanation for the swollen presidency. Americans and their legislators, being human, are awed by the spectacle of power. That is why those who are suspicious of power should not love this parade, whether or not they like Mr. Trump. The best reason for concern about the parade may be that a president, and not merely this president, proposed it.

There are more pressing issues of military policy, but this one is an important constitutional symbol. There are, of course, occasions for military celebrations. Victory is usually the chief one. But the pageant of arms being prepared at Mr. Trump’s direction has no particular cause. It is a show of might, plain and simple. As such, it cannot help but adulate the person of the president who will command all that he surveys.

After-the-fact justifications for the proposed Veterans Day parade included celebrating the 100th anniversary of the end of World War I and the century of American power that followed. House Republicans resorted to the old fallback that opposing the parade would disrespect the troops, who for too long “have been victims of political discord.” They have? The military is among the most respected institutions in society, will receive more than $700 billion over the next fiscal year and does not need the additional currency that contemporary politics prizes most: victimhood.