of performative preoccupation with budgetary discipline
Maybe I'm not clear on what you're trying to say, but I disagree that the current Republican "performative preoccupation with budgetary discipline" can be traced back to Eisenhower. Federal debt as a percentage of GDP went down substantially during his presidency, and Eisenhower resisted tax cuts proposed by others in the party in favor of a balanced budget. Obviously Eisenhower was helped by a growing economy, but I can't imagine Reagan, Bush II, or Trump would have passed up the chance to pass a major tax cut (and in fact, Democrats cut taxes substantially after Eisenhower left office).
I'd argue that the current Republican approach to the budget can be traced to the Reagan Era, when Republicans began emphasizing tax cuts above all else, and when debt as a percentage of GDP almost doubled (from 1981 to 1993).