The final projections for the 2020 election brought with them a new electoral map, one that highlights the changing shape of America and the divisions that now define the Democratic and Republican parties in the Trump era.

President-elect Joe Biden took back three Northern states — Pennsylvania, Michigan and Wisconsin — that President Trump carried in 2016. He also scored important breakthroughs in the Sun Belt with victories in Georgia and Arizona. Meanwhile, Trump established more secure beachheads for the GOP in Ohio and Iowa, and he again dashed Democrats’ hopes of winning Florida and North Carolina.

The new map gives Biden 306 electoral votes, exactly the number that Trump earned in his surprise victory four years ago. Some of the changes are certainly a function of underlying trends in the nation’s politics, changing demographics and shifting allegiances of suburban or White working-class voters. But they are also a function of Trump’s norm-busting presidency. How big the Trump factor has been will have to await the 2024 campaign or beyond.

The electoral map is never truly static. Four decades ago, there was plenty written about a so-called Republican lock on the electoral college. This was at a time when Ronald Reagan won 489 and 525 electoral votes in 1980 and 1984 and George H.W. Bush grabbed 426 in 1988. Some analysts speculated that the Democrats might not win the presidency for years, if ever.

That talk ended abruptly in 1992, when Bill Clinton made Bush a one-term president and started a shift in the electoral map in the Democrats’ favor. Eventually, Democrats were able to build what journalist Ronald Brownstein would call the “blue wall” — 18 states and the District of Columbia — that voted for Democratic presidential nominees in every election between 1992 and 2012 and that at the start of the 2016 election added up to 242 electoral votes.

Democrats won four of the six presidential elections from 1992 to 2012, and the popular vote in five of those six. But neither Clinton nor Barack Obama came close to amassing the electoral vote majorities of the Republicans in the 1980s: Clinton’s best was 379 in 1996; Obama’s best was 365 in 2008. In between them, George W. Bush did even worse, managing only 271 electoral votes in 2000, while losing the popular vote, and 286 in his 2004 reelection bid. These narrower electoral college majorities all signaled a country that was becoming increasingly polarized.

The Clinton years brought significant changes in the voting patterns of important states. Republicans won California in seven of eight presidential elections from 1960 to 1988. Democrats have won the state ever since. Illinois voted mostly Republican in those same election years, but it has been solidly Democratic since Clinton’s 1992 victory. The same is true of New Jersey.

Beginning in the Obama years, Colorado and Virginia began to shift. Once a purple state, Colorado backed Biden by 13 points this year. Virginia, solidly red until Obama won there in 2008, has also moved into the Democrats’ column. Hillary Clinton won it by five points in 2016. Biden won it by nearly 10 points this year.

Biden’s victories in Georgia and Arizona, which have a combined 27 electoral votes, have enormous implications for the future of presidential campaigns. Strategists in both parties have eyed both states in recent elections as two that, with the right conditions, could flip from red to blue. Changing demographics, suburban growth and organizing efforts by liberal groups were the underlying forces, but suburban voters’ revulsion to Trump also made possible Biden’s narrow victories in both states.

Texas is the other Sun Belt state that is in transition but still tilts in the Republicans’ direction, as the results there this month showed.

Democrats had high hopes for Texas, cautiously so presidentially but more so for congressional races. Instead, Texas proved to be a massive disappointment for the Democrats. None of the competitive House seats flipped. Still, Trump’s six-point victory margin over Biden was the smallest there since 1996, when the independent candidacy of Texan Ross Perot held the GOP margin to five points.

Democrats have been talking about turning Texas blue for nearly a decade, on the assumption that a fast-growing Hispanic population and suburban growth would finally make it possible for Democrats to win statewide elections. But this year’s election saw Latino voters in South Texas support Trump in surprisingly large percentages, underscoring the danger of assuming that voting patterns among various groups of voters will remain constant indefinitely.

Georgia and Arizona will certainly be competitive in future elections. As this year proved, that gives a Democratic candidate more options to assemble the necessary 270 electoral votes to win the White House. Add Texas to that mix, with its current 38 electoral votes (and several more after the 2020 census reapportionment) and the Republicans would find themselves on the defensive in what has long been their stronghold.

But a competitive state is hardly one that can be counted on consistently. Biden’s success in Georgia and Arizona stems in part from the fact that he was running against Trump. Will Southern suburban voters find a different Democratic nominee, one who is pitted against a Republican not named Trump, as appealing? Biden’s victory margin in both states is by less than half a percentage point — and Georgia has announced a hand recount of its more than 5 million ballots before the results are certified.

These Sun Belt states represent expansion opportunities for the Democrats. Up north, they could find themselves in a more defensive posture. Ohio and Iowa showed the beginnings of that. Biden was successful in rebuilding the blue wall by winning Pennsylvania, Michigan and Wisconsin, but Republicans see those states as more akin to swing states rather than solid bricks in that wall.

Trump won Wisconsin by less than a percentage point in 2016, and Biden won it by less than a point this year. George W. Bush twice lost it by less than a point. Trump won Michigan four years ago by less than a point. Biden’s margin is less than three. Pennsylvania was a less-than-one-point state four years ago and a one-point state this year. All three will be hard fought in the future, and Democrats cannot take any for granted.

Both Biden and Trump were seen as factors in the outcome of those three crucial Northern states this year: Biden supposedly as a candidate with greater appeal to White ­working-class voters than perhaps would have been the case with another Democrat; Trump as someone who energized suburban White voters to come out and vote against him.

However, exit polls in Pennsylvania show that Biden’s victory came not from big inroads among White voters without college degrees. He lost them by about the same margin — 32 points — as Hillary Clinton did in 2016. And in 2020, those voters made up 45 percent of the Pennsylvania electorate, compared with 40 percent in 2016. Biden won with Black votes in Philadelphia and a larger share of the suburban vote around Philadelphia than Clinton four years ago.

One major question is whether, without Trump on the ballot in the future, suburban voters — especially White women with college degrees — will remain strongly Democratic or revert to previous patterns as a key swing vote? Results of some House races suggest Trump was a bigger problem for some suburban voters than the Republican brand itself.

Similarly, without Trump, will White voters without college degrees remain as strongly Republican as they have been? Or has there been a culture shift among those voters away from Democrats that will live on post-Trump? Some Democrats fear that White voters without college degrees may be lost to them indefinitely, even if Trump fades from the scene, unless they find ways to engage them more effectively.

Some clues will emerge in the 2022 midterm elections, but real answers will have to wait until 2024.