It’s hardly novel to see the electorate as split into three groups: one side, the other side, and those in the middle. This presidential election can certainly be seen in this way, though the groups are now a bit asymmetric: The side passionately supporting President Trump is about 35 percent of voters; the side adamantly opposed to him represents about 45 percent; and the middle is somewhere between 15 and 20 percent. These numbers are derived from measuring those who strongly approve or disapprove of his performance, as well as those who say they'll definitely support or definitely oppose his reelection.

A national poll released by Monmouth University this week showed many voters in the middle moving away from Trump. Thirty-seven percent of registered voters surveyed thought that “President Trump should be re-elected,” while 60 percent felt it was “time to have someone else in office."

Trial-heat polling, both nationally and in key states, also underscores the president's challenges. Today Trump is not ahead or tied in any of the 20 states (plus D.C.) carried by Hillary Clinton in 2016. Worse yet, he trails in Michigan, Pennsylvania, and Wisconsin, the states that effectively determined the outcome of the 2016 election. In fact, Trump apparently lags in polls conducted for his reelection campaign in 17 swing or potentially swing states. In terms of national polling, the May 11-14 Fox News survey showed Trump trailing former Vice President Joe Biden by 11 points nationally (38 to 49 percent) and Sen. Bernie Sanders by 5 points (41-46 percent). Against lesser known Democrats, the poll found him running 2 points behind Sen. Elizabeth Warren (41-43 percent) and just a point ahead of South Bend, Indiana Mayor Pete Buttigieg (41-40 percent).

But what will that 15 to 20 percent in the middle be thinking about when they actually begin to focus on the race? This is hardly a monolithic group that will simultaneously pick up and move in the same direction, but what will the preponderance of voters do, keeping in mind that Trump needs to win between two-thirds and three-quarters of them?

Republicans should hope they don't look at Trump and his administration and focus on the three C’s: chaos, conflict, and competence. Do they see the president and his team on top of the job, knowledgeable, possessing the right skill set and addressing problems in an organized and disciplined way—or, not so much? The old line about “no drama Obama” was more right than not. These days, the atmosphere of the White House is more like that of a soap opera, or even the WWE.

Notice the absence of scandal in this narrative. Those voters obsessed about Russia, emolument clauses, obstruction of justice, collusion, or any other allegations—those who see a “moral imperative” to impeach the president—are fully baked into the 45-47 percent who adamantly oppose him. The group of voters in the middle don’t love or hate Trump; they just want things to function.

To the extent that voters are focused on these questions, some Democratic candidates might be better than others in addressing them, while others might bring their own baggage into the race, allowing focus to be shifted to a choice between two flawed nominees. This is exactly what Republicans are hoping for, while Democrats look to make this election a referendum on Trump. Don’t forget that 221 out of 222 national polls conducted since Trump took office—by ABC News/Washington Post, CBS News, CNN, Fox News, Gallup, NBC News/Wall Street Journal, and Pew Research—have shown his disapprovals higher than his approvals, and none have given him a majority approval at any point. Needless to say, no president in polling has had this situation.

The age-old debate over whether it is better to nominate a candidate who can motivate the party base or one who reaches into the middle, appealing to independent and other swing voters, is presenting a choice of walking or chewing gum—you have to do both. Where these things come into conflict is that the issues that most motivate the base, whether within the Democratic Party or the Republican Party, are often ones that grate on the nonideological, or at least less ideology-driven, voters in the middle.

Trump has clearly picked the base-motivation model, effectively conceding the middle ground to Democrats—if they choose to take it.