The big field of Democrats running for president in 2020 has big plans for American democracy. Most support, or are "open to," a head-spinning array of changes to the way U.S. elections are run and the country is governed.

Among the renovations planned: sweeping new constitutional powers for Congress to restrict election spending; an expansion of Supreme Court membership to alter its philosophy; term limits for Supreme Court justices; elimination of the Senate filibuster; lowering the voting age to 16 — and, of course, that most popular remedy for what ails America, abolition of the Electoral College.

None of these transformations would be easily accomplished, not least because they might inspire second thoughts if they actually came close to becoming reality. Anyway, let's hope they would.

Today's self-assured improvers of democracy are zealously impatient with the complicated institutional devices America's Framers put in place to restrain public passions and guard against what John Adams called "tyranny of the majority." The Framers' aim, James Madison wrote, was to construct checks and balances with which the majority would be divided, when throwing its weight around politically, into "many parts, interests, and classes of citizens … " That way only broadly shared, carefully considered and lasting majority wishes would become law.

Among today's re-invention proposals, elimination of the Electoral College deserves the most attention, partly because it's so candidly about increasing majority power, and partly because a clever mechanism has been devised that conceivably could circumvent the Constitution and establish a nationwide popular vote as the de facto method for electing future presidents.

Fourteen states have enacted laws joining an interstate compact, under which each member state would henceforth allocate all of its Electoral College votes to the winner of the nationwide popular vote for president. The agreement would take effect when enough states had signed up to give the top popular vote-getter a majority of 270 electoral votes, and hence the White House.

Will enough states sign on? If they do, might this arrangement itself be found unconstitutional as the kind of "Compact" the Constitution (Article I, Section 10) forbids among states without the approval of Congress? Time may tell, but it all bears watching. (A bill to join the agreement is before the Minnesota Legislature, as it has been for some years.)

To back up, the main thing that is detested about the Electoral College is that, while boosting the influence of smaller states, it occasionally has awarded the presidency to a candidate who finished second in the nationwide popular vote. Under the college system, a presidential election is really 50 separate state elections, and 48 of 50 states bestow all their electoral votes on the winner of their statewide tallies. (It's thought the contest in each state becomes more important that way.)

The college has denied victory to the popular vote winner four times since the Civil War — and two of those elections have come since 2000, putting George W. Bush and Donald Trump in the White House, understandably inflaming the system's modern liberal critics.

But those critics seldom feel any need to explain why a nationwide popular vote should be seen as the natural or supremely legitimate way to measure the will of the electorate. The simple fact of the matter is this: From our republic's birth, America's many framers — the many designers and reformers of American institutions and processes for electing public officials and resolving public issues — have never found a single type of question that they judged would be best submitted to a nationwide popular vote.

Madison's complex union of "many parts, interests and classes of citizens" conducts many statewide popular votes within the separate states, and many other elections within smaller representative districts. Legislatures have been empowered to ratify constitutional amendments state-by-state on their people's behalf and, in earlier days, to indirectly choose U.S. senators.

But a vote decided by the will of a simple, consolidated national majority has never been thought to reflect the type of nation America is.

The challenge for America has always been to peaceably govern a hugely varied population — crowded in pulsating cites and spread across lonesome frontiers — under a single regime. To balance vast differences in interests and sensibilities, political representation can't be based solely on rigid head-count equality; it has to recognize that rights and autonomy belong not only to individuals but also to communities of place, belief and walk of life. All geographic political districting — for Congress, legislatures, city councils, etc. — reflects this understanding and denies total power to the consolidated at-large majorities of larger jurisdictions.

The Electoral College, by giving states, as distinct polities, a role in choosing presidents, forces presidents and would-be presidents to concern themselves with diverse concerns across America. Under a nationwide popular vote system, maximizing support and vote totals in highly populous and ideologically monolithic regions would become the chief preoccupation of presidential hopefuls.

Consider the 2016 election. It is endlessly noted that Hillary Clinton received nearly 3 million more individual votes than Donald Trump nationwide. Seldom is it observed that Clinton enjoyed an even larger margin, more than 4 million votes ... within California. In other words, in the other 49 states (considered as a whole), Trump got more individual votes.

Fact is, Clinton collected her "nationwide" margin in just five big blue California counties around the Bay Area and Los Angeles, in each of which she carried more than 70 percent of the vote.

There is another possible error in insisting Clinton "won the popular vote." Once a contest is settled, it is illogical to assume that the losing party would have won if only the rules for deciding the contest had been different. Had the rules been different, all the contestants would have employed different strategies. Guessing the outcome is, well, guesswork.

At the end of a baseball game, you could insist that the losing team "would have won" if stolen bases had been what counted as "runs" instead of circling the diamond and reaching home plate. But the winning team would reasonably protest that under those alternative rules they would have put more speedsters and fewer sluggers in their lineup.

The game, in short, would change quite a lot under different rules. And if a nationwide popular vote replaced the Electoral College, presidential politics would also change quite a lot, along perhaps with the presidency itself and the pressures and incentives influencing those who hold and seek the office.

How carefully have today's confident theorists evaluated whether all those changes would be for the better?

D.J. Tice is at Doug.Tice@startribune.com.