CNN  — 

Sen. Ron Wyden accused President Donald Trump of assembling an “enemies list” of critics through his efforts to strip a half-dozen national security officials of their security clearances.

Trump is considering taking away the security clearances of several former national security officials who have been publicly critical of him, White House press secretary Sarah Sanders announced at a press briefing Monday. The former officials have “politicized, and in some cases, monetized their public service,” Sanders said. “Making baseless accusations of an improper relationship with Russia is inappropriate.”

“As I listen to this, it sounds to me like Donald Trump is talking about building an enemies list,” Wyden, an Oregon Democrat, said on CNN’s “Erin Burnett OutFront.” “This is just plain wrong. The idea, and that’s why I characterize it, of building an enemies list in order to look at the possibility or strategize ways to go after your critics is contrary to everything that our country is all about.”

The term “enemies list” harkens back to the tenure of President Richard Nixon, who had his aides keep an “enemies list” of politicians, journalists and entertainers who Nixon felt had wronged him.

When asked whether stripping the officials of their clearances could be grounds for impeachment, Wyden told Burnett that all options would be on the table if Trump used taxpayer funds to retaliate against critics.

“If he goes forward with what he’s been talking about today, the idea of building an enemies list, and then we’d have the prospect of whether taxpayer funds were being used to deal with critics, I would rule absolutely nothing out if he pursued that strategy,” the Oregon Democrat said.

Wyden encouraged Republicans in Congress to join with Democrats in speaking up to stop Trump from attacking critics.

“Obviously, we’re going to have to have Republicans get serious about pushing back. I mean again and again they have made excuses,” he said. “I just hope that … Republicans will come to their senses on some of these issues.”