(Note: The writer is answering the question: “Will attacks by Democratic progressives on Joe Biden help re-elect President Trump in 2020?”)

WASHINGTON — Donald Trump’s presidential luster has diminished only slightly since he formally declared his 2020 candidacy in April.

But that hasn’t kept other Democrats — more than 20 of them, at last count — from jumping into the presidential race to oppose former Vice President Joe Biden, the current front-runner.

That sets up an interesting dynamic: From now until the conclusion of the Democratic primaries, nearly two dozen candidates will be running to drag down Biden’s poll numbers, mostly from his left.

His top challengers are identity-politics progressives and a socialist — Vermont Sen. Bernie Sanders, who honeymooned in the Soviet Union. Even if they fail, they could weaken Biden ahead of a general election matchup against President Donald Trump.

Biden’s chief asset is that he can appeal to the working-class whites who live in the industrial states like Michigan and Pennsylvania that narrowly handed Trump the 2016 presidential election.

That’s because Biden is respectful of their cultural conservatism even if he doesn’t share it and is generally a throwback to an older Democratic politics from less Trumpy and tumultuous times.

Many on the left, however, want to match Trump tweet for tweet. They are angry at the status quo and want a Democratic nominee who shares their anger. They also want an unapologetic defense of abortion rights, even in later stages of pregnancy, rather than outreach to blue-collar Catholics in the Rust Belt.

They see climate change and gun violence as existential crises to be confronted head-on, not wedge issues to be carefully messaged to hunters and coal miners in swing states. If it was up to these progressives, Trump won’t even be on the ballot come 2020, because he will already have been impeached.

Democrats know they can run to the left of Bill Clinton and win. Barack Obama proved it. What is less certain is how far to the left of Obama can get they go and still win — but progressives would like to find out.

Many Democrats are running not on Obamacare but Medicare for all. Some would abolish Immigration and Customs Enforcement; most would go further than Obama did in liberalizing immigration laws. The price tag of the Green New Deal makes Obama’s stimulus program look miserly.

Yet the objective won’t be to emphasize Biden’s commonalities with Obama, who is still mostly beloved by progressives. It will be to tie him to the Clintons’ centrist politics, which are increasingly rejected by the Democratic base and failed in the last election.

Biden was chummy with Republicans and even Southern Democrats who had once supported segregation. And as the top Democrat on both the Senate Judiciary and then Foreign Relations Committees, Biden bore more responsibility for the 1994 crime bill and the war in Iraq than did Hillary Clinton.

A strong progressive push against Biden may force him to apologize for issue positions that resonate with the voters likely to decide the election and abandon the bipartisan tone that contrasts him so favorably with Trump.

It will also help Trump hit Biden on Iraq, the crime bill, trade and other issues the president previously used successfully against Hillary Clinton.

Some Democrats won’t vote, others will go third-party and a few in the right places might even pull the lever for Trump as a result.

Progressives will undoubtedly argue that this is why Democrats should not nominate a presidential candidate who would be vulnerable to Trump on these issues in the first place and turn to one of their preferred contenders instead.

But that strategy also is risky: what if progressives are wrong in their belief that the country is ready to elect a president to the left of Obama?

Socialism, reparations for slavery, programs that may require tax increases on families who are not wealthy, even impeachment could all backfire at the ballot box or inspire a third-party centrist to run, handing Trump a second term.

W. James Antle III is the editor of American Conservative magazine. Readers may write him at The American Conservative, 910 17th Street, NW, Suite 312, Washington, DC 20006-2626.