Seven and a half years after the passage of the Affordable Care Act, and five years after the Supreme Court gave its central provision a stamp of legal approval, America is still fighting over the individual mandate. The debate over the requirement to maintain health coverage or pay a penalty has become a permanent feature of American political life — a debate from which we seemingly cannot escape.

At the moment, much of the debate revolves around the mandate’s potential impact on tax reform: Senate Republicans, prodded by President Trump, will include a repeal of the mandate in their tax legislation. Mr. Trump, meanwhile, is reportedly at work on an executive order to weaken the mandate if Congress does not take action.

Democrats are warning that to do so would be to undermine the health care law and end coverage for millions. The accuracy of the Congressional Budget Office model estimating the provision’s cost and coverage effects is a major point of contention.

To the sort of casual observer who is blessed to not follow legislative markups and daily Twitter skirmishes over C.B.O. scores, these debates might look both predictably partisan and boringly technical — and often they are. But they also serve as recurring reminders of the many ways in which the mandate has inserted itself into our national political consciousness, its ripple effects touching not only health care but also tax legislation and federal debt and deficit calculations.