Senator Cory Booker (D-NJ) testifies to the Senate Judiciary Committee during the second day of confirmation hearings on Senator Jeff Sessions' (R-AL) nomination to be U.S. attorney general in Washington, January 11, 2017.

All year long, struggles within Congress and the White House on health care, taxes, trade and infrastructure have highlighted deep fissures in the Trump-era GOP.

For the moment, they've obscured divisions within a Democratic opposition savoring the luxury of just attacking.

But those divisions will surface soon enough, as the 2018 mid-term election campaign accelerates and the 2020 presidential contest gets underway. And when they do, a recent examination of both parties suggests, they will produce some surprising Democratic beneficiaries.

The examination, by a team of analysts across the political spectrum for the Voter Study Group, shows how the surge of President Donald Trump's blue-collar backers has buffeted the GOP. They diverge from the party's traditional conservatism on taxes, spending and trade.

Democrats have their own fault lines, as the party's protracted 2016 primary battle made clear.

But the report concluded that the party's rank-and-file chose between establishment figure Hillary Clinton and self-styled revolutionary Bernie Sanders on the basis of style more than substance.

Though Sanders' supporters were more hostile to international trade agreements, they held similar views to Clinton's allies on core economic concerns such as income inequality and the importance of an activist government.

"Their voters were not all that different on most issues," wrote Lee Drutman, a fellow at the New America think tank who was part of the Voter Study Group team. "To the extent that the Democratic Party is divided, these divisions are more about faith in the political system and general disaffection than they are about issue positions."

Thus attitude may represent the key variable within Democratic politics over the next three years. Already, some Democrats have staked out divergent positions on how vehemently to resist the agenda of Trump and the GOP Congress.

After Democrat Jon Ossoff struck a temperate tone in his losing race for a Georgia House seat, some intraparty critics complained that he should have excoriated the president more. The recent fight for Virginia's Democratic gubernatorial nomination — in which Sanders-backed former House Democrat Tom Perriello lost to Lt. Gov. Ralph Northam — revolved around who had greater ability to produce change.

The Virginia outcome suggests that firebrands in the mold of Sanders and Massachusetts Sen. Elizabeth Warren may have less momentum within the party than they assumed in the wake of Trump's triumph. Like the Republican president, each has drawn energy with angry complaints that the political system is rigged to the detriment of average Americans.

However hostile the party's feelings about Trump, their challenge may get even steeper the closer the nation draws to the 2020 presidential contest. David Axelrod, the chief strategist in Barack Obama's breakthrough 2008 victory, notes a recurrent pattern: Voters seek qualities in their next president that compensate for what they consider defects in the last one.

Thus in 2000, they embraced George W. Bush's vow to restore "honor and dignity" to a White House tarnished by Bill Clinton's scandal. In 2008, they turned to Obama's deliberation over Bush's "gut-player" style. In 2016, an electoral majority opted for the bombast of a wealthy outsider vowing to "make America great again."

"In 2020, there will be a market for an antidote to him," Axelrod said. That points toward a quieter, more thoughtful approach that places a higher premium on governing experience.

"There will be a receptivity to someone who offers big ideas about how to insure a fair shot and economic security for the broadest number of Americans in a rapidly changing economy, rather than promising a return to an irretrievable past," Axelrod said. "There will be a market for a more healing and unifying figure who can speak to our common values and concerns as Americans rather than mining resentment and sowing antagonism."

If he's right, harsh denunciations of the wealthiest 1 percent won't prove the most effective Democratic answer to Trump's denunciations of illegal immigrants. That dynamic would give an advantage to potential White House candidates with a more consensus-oriented message, such as Joe Biden or Cory Booker, rather than Sanders or Warren.