Four years ago, when Republicans nominated Donald Trump for President, some optimistic Democrats envisioned a rout at the top of the ticket, with coattails that could install a blue majority in the United States Senate.

Outraged Democrats would flock to the polls, the theory went, while independents would vote a Democratic ticket, and reasonable Republicans would sit out Election Day. That would not only give Hillary Clinton a decisive victory, but tip several close Senate races—in Missouri, Pennsylvania, Wisconsin, and elsewhere—to Democrats.

It didn’t happen that way, of course. Rather than a rout, it was a close election with a variety of factors narrowly tipping the popular vote in Clinton’s favor, and the electoral college in Trump’s.

Signs of a widespread rejection of Trump—the type that would bring a truly lopsided result—never appeared. Though only about 35 percent had a favorable opinion of him, that number didn’t drop to the low 20s as it did for Richard Nixon’s approval rating during Watergate, or George W. Bush’s after the financial collapse. Republican and conservative leaders didn’t abandon him to endorse Clinton.

Few other Republicans on the ballot distanced themselves from him. And turnout patterns revealed that enthusiasm for Trump equaled, or exceeded, enthusiasm against him.

Those signs continue to speak volumes with their absence. No wonder that pundits expect another close Presidential race, and slim hopes for Democrats to gain the three seats needed (assuming they also win the Presidency, and with it the tie-breaking vote) to secure control of the Senate next year.

As for Democrats, the severe dashing of those hopes in 2016 has left most of them scarred, unable to dare think positively about their 2020 chances.

But, it’s just possible that this will turn out to be the election that some mistakenly envisioned three years ago: an anti-Trump landslide that, in its wake, leaves Democrats in control of the U.S. Senate.

They need what recent events may have opened the door to: a major shift in the message Americans want to send to Trump, when they get their chance at the ballot box.

That shift hasn’t happened yet, to be sure; and the smart money says it never will.

Trump is trailing in early 2020 polling, nationally and in crucial swing states, but within the range of a normal, competitive election. His job approval rating remains stable in the low- to mid-40s. And almost no cracks have developed among Republican and conservative leaders.

Nevertheless, the current crisis holds the potential—for now, just the potential—to change all that. Already, polls show nearly half the country in favor of Trump’s impeachment and removal, while some GOP officeholders are displaying less than full-throated support.

As more comes out—not only about what Trump has done recently, but what he continues to do in real-time as pressure builds—the country could easily reach a tipping point against him.

That could turn the 2020 election into something very different—the kind of landslide that would give Democrats not just the Presidency, but a majority in the U.S. Senate as well.

That would be a very big deal. In less than five years since Republicans gained their Senate majority, Majority Leader Mitch McConnell and his cohorts have demonstrated how effectively they can thwart a President of the opposing party, control legislation and government budgets, and shape the federal judiciary.

And Democrats could do even more, with even a slim Senate majority, if they follow through on calls to abolish the filibuster rule.

A growing chorus within the party’s leadership—including Elizabeth Warren and some other Presidential contenders—want to abolish that Senate procedure, which requires 60 votes to bring most legislation to a Senate vote.

Defeating Donald Trump, even in a close election, would be enough for most Democrats. Doing that, maintaining control in the House of Representatives, and eliminating the filibuster in a Democratic-majority Senate, would be potentially transformational for the country.

Three paths for 2020

Although it’s awfully early, and a very long way to go, from this distance there appear to be three plausible directions that the 2020 Presidential election could take.

In one scenario, the country remains pretty evenly split, with Republican faith in Trump—and antagonism to the Democratic nominee—balancing Democrats’ enthusiasm for voting out the incumbent. That leads to another close contest, with states going their predictable partisan ways in the electoral college, and, most likely, in their Senate races too.

In a second trajectory, a significant enthusiasm gap forms between the two sides: Democrats become more and more riled up, while many Republican voters weary of defending him. That leads to a solid win for the Democratic nominee. The resulting gap in turnout, along with anti-Trump independent voters ticking off Democrats down the ballot, pushes some additional states into the blue column for this cycle, in both the Presidential and Senate races.

Then there’s the third possibility: a major rejection of the Republican Party. If the current scandals—and others to come—reach a tipping point in public perception, voters might deliver a message not just to Trump but to the party that enabled and protected him. If that happens, watch out. In the first post-Watergate election cycle, Democrats won 23 of 34 Senate races in 1974, and came within a percentage point or so of winning four more—and that was in a mid-term, without the disgraced Republican President on the ballot.

Here are the Senate seats that Democrats could win in each of those three scenarios—each one adding to 43 safe Senate seats they’ll hold beginning in 2021.

Close Presidential race. Three endangered Democrats are likely to survive re-election even in this scenario: Gary Peters of Michigan, Jeanne Shaheen of New Hampshire, and Tina Smith of Minnesota. Plus, Democrats should be considered favorites to defeat Republican Cory Gardner in Colorado.
All four of those states, you’ll notice, were close contests in the 2016 Presidential race, and would be again in this scenario—but the strengths of the three incumbents, and likely Democratic nominee John Hickenlooper in Colorado, should allow them all to run a few points ahead of their party’s Presidential nominee.

Those four wins would give Democrats a total of 47 seats in the Senate.

Solid Democratic Presidential victory. Aside from Gardner, three Republican incumbents are considered potentially vulnerable in 2020: Susan Collins in Maine, Martha McSally in Arizona, and Thom Tillis in North Carolina. Maine went narrowly for Clinton in 2016, while Arizona and North Carolina each went for Trump by just a few percentage points (and in both cases, with Trump getting less than 50 percent of the vote).

In a normal election cycle, it would be tough for Democrats to win any of those three contests. A large enthusiasm gap in the Presidential race, however, would likely put all three into the blue column.
Winning all three would get Democrats to exactly 50 seats—giving them control, with the Democratic Vice President breaking the tie. No room for error, though.

Total GOP rejection. As deep-red as you might think most red states are, there are more than a half-dozen additional Senate seats winnable by Democrats next year, if 2020 becomes a national punishment election for Republicans.

One is unlikely Democratic incumbent Doug Jones of Alabama, who won a fluky 2017 special election over Roy Moore. Two more are right next door in the Deep South: Georgia, where Republican David Purdue is up for re-election, and a special election will be held for the seat that Johnny Isakson is retiring from at the end of this year. Georgia’s Democratic drift is usually wishful thinking, but in this scenario could flip two seats at once.

Add Jodi Ernst of Iowa and John Cornyn of Texas to the endangered list in this atmosphere too, and perhaps two open red-state seats, where Pat Roberts of Kansas and Lamar Alexander of Tennessee are not seeking re-election.

Oh, and one more: Senate majority leader Mitch McConnell of Kentucky. In that 1974 post-Watergate election, Republican Senate minority leader Hugh Scott of Pennsylvania may have been lucky to not be up for re-election. (He then retired rather than run in 1976.) McConnell doesn’t have that luck—and Democrats would love to send him back home.