(CNN) Make no mistake -- President Donald Trump is the most radical choice in the 2020 election. For all the talk about Democrats trying to figure out whether to nominate a "radical" candidate or a "moderate" one, it's, in fact, the Republican Party that has already made its choice to veer so far from the center of American politics that Sens. Bernie Sanders and Elizabeth Warren pale in comparison to the man who currently holds the highest office in the land.

The media tends to characterize President Trump by describing him as "unconventional" or "unstable," rather than radical. In doing so, they tend to ignore the most defining element of his presidency and the direction the Republican Party has taken. The pollsters who have focused on asking whether candidates like Sanders or Warren are too radical to be elected should also ask voters whether they think our democracy can withstand the radicalism of Trump for four more years.

Trump has tweeted quotes from climate change deniers rolled back federal regulations that curb greenhouse gas emissions and appointed officials who are skeptical about the scientific consensus on this problem.

Meanwhile, a majority of Americans accept the reality and danger of climate change. In 2019, a Washington Post and Kaiser Foundation poll found that 8 in 10 Americans believe that humans are responsible for climate change and two-thirds agree that the US government is doing too little to reduce greenhouse gas emissions.

Trump's radicalism is evident in many other issues. The President has shifted immigration policy sharply to the right and abandoned the efforts of the last two administrations (one Republican, the other Democratic) to create a path to citizenship for the millions of undocumented immigrants living in the US. In addition to scrapping Deferred Action for Childhood Arrivals (its future is still being decided in the courts), the Trump administration has pursued stringent border policies including family separation and the use of elite forces to conduct arrests in sanctuary cities . Under President Trump, the center has shifted to the right.

Despite his promise to help working-class Americans, the President has quietly eliminated workplace safety rules for everyday workers -- dismantling the foundation of worker protections in favor of lifting the fortunes of businesses that may find these regulations burdensome.

During the government shutdown in 2019, for example, the administration got rid of a 2016 rule that required employers to provide the Department of Labor with reports about workplace injuries. The Occupational Safety and Health Administration has the lowest number of inspectors in its decadeslong history, and enforcement efforts have declined, according to the National Employment Law Project

The President has repeatedly rejected any sort of substantive gun control regulations, despite horrific mass shootings. With upward of 64% of Americans supporting tougher gun control laws, the President has stood with an extreme faction of politicians who say no to any real change in the regulatory status quo.

After repeatedly backing away from his promise to impose tougher background checks, the President is now campaigning as an ardent champion of the Second Amendment, telling audiences at rallies that Democrats will "take your guns away."

And on foreign policy, the President has pursued a dangerous unilateral approach that goes against the internationalist strategy presidents in both parties relied on since the end of World War II. While the President has not achieved all of his goals, his attacks on NATO and other vital institutions mark a dramatic break in American strategy.

Trump has also embraced a radical understanding of presidential power. The defense during the Senate impeachment trial made clear that this President does not believe there are many legitimate restraints on what he can do. It appears the lesson Trump learned from Watergate was not that Richard Nixon was wrong in how he conducted himself, but that he did not go far enough.

Sen. Susan Collins thought that Trump would be tamed by impeachment, but so far the evidence suggests that he is only wielding the power of his office more aggressively. Earlier this week, Trump used the Department of Justice as a battering ram to continue the effort to collect dirt on Joe Biden and railed against the recommended sentencing for his old friend Roger Stone, who was convicted of witness tampering, perjury and obstruction.

Meanwhile, US Attorney General Bill Barr has assigned an outside prosecutor to review the case against former national security adviser Michael Flynn. In taking on these cases involving the President's inner circle of advisers, Barr has been willing to interfere in politically sensitive matters involving the White House that attorneys general since Watergate have tried to avoid.

On Thursday, Barr, one of the most loyal administration members, issued a remarkable rebuke on television and said that Trump's tweets make it "impossible to do my job." But the President doubled down, tweeting out that he has a "legal right" to intervene in criminal cases.

Even Trump's rhetoric is radical. One of the most important elements of presidential leadership comes in the form of interviews, public addresses and written pronouncements -- all of which carry great weight. All presidents have abided by a certain set of unwritten guidelines when it comes to decorum. The President has thrown all of that out the window. He has normalized a toxic form of presidential speech that undermines our civic culture.

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In an age when all presidents have expanded the power of their office, Trump is taking things further than his predecessors, shredding any remaining sense of limitations and acting in ways that openly defy the right of Congress, as an equal branch of government, to hold him back.

While he has benefited from a Republican Party that is totally on board with what he is doing, that should not mask the dramatic and radical nature of his strategy. He is acting in dangerous ways that undermine the rule of law and establishing consequential precedents.

Although Democrats are far from settling on their 2020 presidential nominee, we already know what the radical choice will be in 2020: reelecting Trump. When it comes to public policy and use of political power, no candidate, including Sen. Sanders, would come close to matching the radicalism of the incumbent President.