Washington Post columnist explains why some Republican must take on Trump in the 2020 primary
President Donald J. Trump walks across the South Lawn of the White House Sunday, March 25, 2018, returning home from his trip to New York. (Official White House Photo by Andrea Hanks)

Washington Post columnist Michael Gerson explained that it is going to be challenging for Republicans to run against President Donald Trump in 2020.

"Republicans thinking about opposing President Trump in the 2020 primaries are facing the hardest of political choices," he wrote.

"Toppling a sitting president of your own party is a maneuver with the highest degree of difficulty," Gerson said. "So why undertake this difficult, perhaps thankless, political task?"

He added, "At this stage of the 2020 campaign, the Republican case against Trump is not mainly about policy or ideology (though it could be, eventually). It is not primarily about his ignorance and refusal to either learn or improve at his job (though that is concerning)."

"The main Republican argument against Trump is this: He is a person of horrible character who corrupts everyone around him, undermines essential social standards and is branding his party with an image of bigotry that will last a generation," he wrote.

He added, "This is the main reason a Republican on that list (or some talented candidate still unknown) must run. There needs to be an alternative focus of intellectual energy and moral leadership in America’s party of the right. This is what a presidential campaign — successful or not — can accomplish."

Read the full column here.