One year ago, as Donald Trump was preparing to take the oath of office, Democrats were in disarray. Supporters of 2016 nominee Hillary Clinton and Vermont Sen. Bernie Sanders were pointing fingers at each other, the Democratic National Committee was in disgrace, and Democratic voters were demoralized.

Now, Trump has succeeded in doing something extraordinary, something neither Clinton nor House Minority Leader Nancy Pelosi could do — he has united and energized Democrats.

This has occurred in spite of a growing economy, a booming stock market, a shrinking unemployment rate and tax cuts intended to stimulate even more growth.

Trump’s appeal

While economic dislocations and low wage growth certainly played a role in boosting Trump’s presidential run, it was his view of America that mobilized key voters behind his anti-establishment candidacy.

Trump voters were angry about how the country has changed. They saw liberals encouraging diversity (through same-sex marriage, transgender rights and immigration) at the expense of traditional values, roles and institutions (e.g., traditional religious beliefs and organizations).

Even worse, Republicans were unable to roll back or stop the tide of change. Trump’s cultural populism was an important part of his campaign message, and it continues to underlie his appeal to older, less educated, white voters, particularly those in rural areas.

His anti-elitist message resonated with Americans who regarded diversity and political correctness as threats to their traditions and way of life.

His promise to replace “Happy Holidays” with “Merry Christmas” may seem trivial, but it encapsulated an important part of his message and allure, which essentially involved his promise to turn back the clock.

Trump’s threat

But while those themes certainly struck a chord with conservatives and older voters in 2016, they have also — for a very different reason — now energized the young, people of color and more liberal voters, who see Trump’s America as a threat rather than an ideal.

Like Trump, President Barack Obama’s great appeal was not his issue positions — though, of course, liberal Democrats agreed with him about health care, government spending and foreign policy.

Instead, it was Obama’s vision for the country — diversity, equality, fairness and bipartisan cooperation — that made him so attractive, even to nonideological voters.

While many Americans remain outraged by Trump’s judicial appointments, efforts to repeal the 2010 health care law, support for corporate tax cuts and decision to open up drilling off the nation’s coasts, his critics have been most offended by his vision for America.

Trump’s inauguration address, comments after the violence in Charlottesville,  Virginia, and insensitivity toward gays and blacks galvanized liberals, immigrants and the young, many of whom were lukewarm about Clinton’s candidacy and failed to vote during the Obama midterms in 2010 and 2014.

This new energy produced an electorate in Virginia in 2017 that looked significantly more like the national electorates of 2008 and 2012 than those of 2010 or 2016.

That is politically dangerous for the GOP, as it was in 2006, when a Democratic electoral wave swept the country.

Trump’s troubles

Trump and congressional Republicans began this election cycle with little room for error heading into the midterms. After all, Clinton won the popular vote by more than 2 points in 2016 even though key Democratic demographic groups underperformed.

But since his election, Trump has made little effort, either substantively or symbolically, to reach out to voters outside his political base.

Yes, his base is loyal, but it remains dangerously small.

The trouble for Trump and his party is that last year’s Virginia gubernatorial election saw strong turnout among younger voters (ages 18-29 and 30-44) and nonwhites.

The surge was particularly strong in suburban areas, where white women with a college degree helped Democrat Ralph Northam sweep to an unexpectedly strong victory.

Trump’s voters went to the polls and supported Republican Ed Gillespie, but he was crushed by almost 9 points by a larger-than-expected Democratic turnout.

The outcome in Virginia revealed the long-term problem for Republicans in general and Trump in particular: the America of Donald Trump isn’t one that is inclusive and welcoming.

It is an America tied to cultural values and behaviors of the 1950s, not the 21st century. That has proved appealing to older white voters, evangelicals, the less educated and those living in rural America, but not so to the rest of the country.

Other elections in 2017 and most national polls have also shown greater Democratic energy and opposition to the president, even with the nation’s good economic numbers.

The Democrats don’t have Obama at the top of the ticket, but they have someone almost as good — Donald Trump.

So, while the president can (and inevitably will) brag about some of his accomplishments, perhaps his greatest accomplishment may be his success in reviving and revitalizing the Democratic Party. And for that, Democrats should thank him.

This column was originally published by Roll Call on January 10, 2018.