Politically, our country is divided into four camps, not two.

Only one of these, largely rooted in rural America and bolstered by ideological conservatives, supports President Trump. Two of them, urban progressives and suburban moderates, strongly oppose him. The last consists of white, blue-collar voters in the industrial states who swung Democratic in significant numbers this year but remain up for grabs.

The future of American politics and the fate of the Democratic Party hang on whether the two anti-Trump blocks can work together — and do so in ways that hold the gains the party made in states such as Pennsylvania, Michigan and Wisconsin.

The contours of our politics help explain the results of Tuesday's Senate runoff in Mississippi, where Republican incumbent Cindy Hyde-Smith defeated former Democratic Rep. Mike Espy.

Seen one way, the result is a depressing reminder of the continuing power of racial polarization. Hyde-Smith beat Espy by a margin of 54 percent to 46 percent despite, to be charitable, racially-charged comments that included an exclamation that were she invited to "a public hanging, I'd be in the front row." They were chilling words in Mississippi, the site of more lynchings — 581 between 1882 and 1968 — than any other state in the union.

Yet Espy, the first African-American congressman from Mississippi since Reconstruction, ran better than past Democratic candidates not only by producing an impressive turnout in predominantly black counties but also by cutting into Republican margins in more urbanized and suburban parts of the state. Hyde-Smith partly offset these gains with overwhelming margins in the white, rural counties that dominate politics in the Magnolia State.

What's striking is that the weakness of a Trumpified GOP among better-educated, suburban voters was on display even in Mississippi, which no one expects to vote for a Democratic presidential candidate anytime soon.

These middle class and upscale voters produced a large new bloc of Democrats in the House of Representatives. Many of the newcomers came from traditionally blue states, but metropolitan districts in the red states of Texas, Oklahoma, Kansas, Utah and Georgia also fell their way. These victories helped account for the Democrats' astonishing popular-vote margin of some 9 million in House contests, and they triumphed in districts that were once hospitable to a moderate brand of Republicanism that has been crushed in the Trump era. You could say that moderate and progressive Republicans now live inside the Democratic Party.

The new wave is exemplified by Abigail Spanberger, a 39-year-old former CIA officer who won a traditionally Republican district based in in the suburbs outside of Richmond, Virginia, by running an explicitly anti-ideological campaign. She told voters directly that "I can't fix every problem," and pledged to seek "common ground" even with those who would cast a ballot against her. Hers was the precise antithesis of Trump's approach to politics.

Politicians such as Spanberger represent the future of the Democratic Party, but so does Ayanna Pressley, 44, a Boston City Council member who ousted a longtime Democratic House incumbent in a Massachusetts primary. Her slogan was uncompromising in its impatience, "Change Can't Wait." Pressley built a coalition of African-Americans, Latinos and young urban professionals motivated not only by opposition to Trump but also by a desire to move politics in a decidedly more progressive direction.

Spanberger and Pressley would do their party a favor by becoming best friends. Democrats will not be able to govern and build a durable majority unless the forces that each represents can find their own brand of common ground. The two might invite into their friend group blue-collar Democrats such as Reps. Brendan Boyle of Pennsylvania and Dan Kildee of Michigan, whose constituencies are the other ingredient to a new political formula.

The three pieces of the large anti-Trump majority that dominated the midterms — urban, suburban professional, and blue-collar voters not sold on Trump — will remain a majority only if each component understands that its success and access to power depends on the well-being of the other parts.

Their solidarity is also essential to an additional requirement for creating a post-Trump future: breaking Republican support for the president.

Democrats such as Spanberger and other newly elected swing-seat colleagues such as Mikie Sherrill in New Jersey and Chrissy Houlahan in Pennsylvania strike fear in the hearts of Republicans who know their party must appeal far beyond rural counties in Mississippi and elsewhere if it is to have a future.

The sooner such Republicans admit that Trumpism is a slow-working political poison, the better off our country will be.

E.J. Dionne