Thanks to President Donald Trump, American voters may flock to the polls in record numbers on Nov. 6 for the next congressional midterm elections. He will not be on the ballot in any of the 435 voting districts, but nevertheless a great many Americans will be casting their ballots to express their opinions of him — for or against.

Both major parties have acknowledged that fact. The Democrats hope to wrest control of one or both houses of Congress as a means to slow or halt Mr. Trump's reign at midterm. The Republicans in response seek to keep it on track.

Either way, the outcome may generate life support for a phase of our democratic process that over the years has fallen into public neglect. Voters still flock to presidential elections every four years, but they often skip the midterms, either out of disinterest or lack of knowledge of House and Senate candidates.

These candidates usually are left to their own efforts, and if lucky to party finances, to campaign for themselves. They drum up news media attention by wile or whimsy, to convince voters to turn out for them on Election Day. Longevity in office may breed familiarity, but first-time challengers often face an uphill climb.

This time around, however, the evolution of the 2018 midterms, after nearly two years of Trump theatrics and governing chaos, has been broadly cast as a national referendum on the sitting president.

The Democrats early on began organizing for the midterms to throttle him with a “blue wave” of voter turnout generated by all manner of anti-Trump motivation. The Republicans have responded with turnout drives of their own for a "red wave," fueled significantly by the embattled president himself on the stump.

The Democrats, reminding the midterm electorate of all of Mr. Trump's personal flights into fancy, false assertions and hostility toward women, racial and ethnic groups, hope to derail his reign at midterm. The Republicans, including unresisting party loyalists seeking re-election in Congress on his coattails, are hanging on, hoping the Trump faithful will keep them in office.

Mr. Trump himself has taken the fight once again to massive campaign rallies in red states and pocket districts, notably in Southern, border and Rust Belt areas that went for him in 2016.

In Iowa last week, citing Democratic senators' opposition to the Supreme Court confirmation of Justice Brett Kavanaugh, Mr. Trump said "an angry left-wing mob" had "become too dangerous to govern," and declared of the midterms: "In four weeks you will have the chance to render your judgment on the Democrats’ outrageous conduct."

When he accused Democratic Sen. Dianne Feinstein of California of leaking the Kavanaugh accuser of sexual assault, the crowd erupted in demands of "Lock Her Up!" in echoes of 2016. Democratic midterm election success, the president declared, would "turn our country so fast into Venezuela."

On Wednesday, as a massive hurricane headed to the Gulf Coast of Florida, Mr. Trump went ahead with another capacity-crowd campaign rally in Erie, Pa., defending his decision, saying he "couldn't disappoint the thousands who waited" there, adding: "We're sending our unwavering love and support to [Hurricane] Michael victims," while maintaining "close coordination" with Florida's governor and local officials.

At the same time, the White House published an op-ed in USA Today in which Mr. Trump sought to position himself as a defender of Medicare for seniors and charging the Democrats with trying to "eviscerate" it. He also misstated some provisions of their "Medicare-for-all" proposal championed Sen. Bernie Sanders of Vermont, the failed 2016 presidential candidate.

That legislation seems an unlikely subject for Mr. Trump on which to seek re-election in 2020, in spite of his failed campaign to totally eradicate Obamacare in the first months of his presidency. Like it or not, the midterms can present the first tangible clue to Mr. Trump's survival in the Oval Office, beyond the Mueller investigation into Russian elections meddling still hovering over him.

Jules Witcover is a syndicated columnist and former long-time writer for The Baltimore Sun. His latest book is "The American Vice Presidency: From Irrelevance to Power" (Smithsonian Books). His email is juleswitcover@comcast.net.