(CNSNews.com) – President Trump’s appointment of Matthew Whitaker as acting attorney general “should concern every American — Democrat, Republican, liberal, conservative — who believes in rule of law and justice,” Senate Minority Leader Chuck Schumer (D-N.Y.) told CNN’s “State of the Union” with Jake Tapper on Sunday.

Schumer said if Whitaker doesn’t recuse himself from the Mueller investigation, Democrats will try to pass a bill preventing Whitaker from interfering in the probe. Schumer said that bill would be attached to a must-pass spending bill.

Schumer said if Whitaker does not recuse himself, “he will create a constitutional crisis by inhibiting Mueller or firing Mueller, even. So, Congress has to act, has to act:

So, we Democrats intend to do two things.

First, today, I am sending a letter, along with Leader Pelosi and some of the other Democrats who are ranking members of their committees in both houses, to the chief ethics officer of the Justice Department, asking him to issue guidelines: Should Whitaker recuse himself from anything involving Mueller?

He issued guidelines like that with Jeff Sessions, and Jeff Sessions recused himself. Whitaker should.

But, second, if that doesn’t happen, we Democrats, House and Senate, will attempt to add to must-pass legislation, in this case the spending bill, legislation that would prevent Mr. Whitaker from interfering with the Mueller investigation.

That legislation has had bipartisan support. Two Democrats and two Republicans introduced it. As you mentioned, the — there are a number of Republicans who have spoken out that we cannot allow Whitaker to interfere with the Mueller investigation.

Those Republicans include Sens. Susan Collins and Jeff Flake.

Democrats say Whitaker has already prejudged Special Counsel Robert Mueller’s Trump-Russia probe by writing an op-ed for CNN in which he said Mueller would be “crossing a line” if he expands his investigation to include the Trump family’s finances.

Host Jake Tapper asked Schumer, “Are you willing to risk shutting down the government and not signing a government spending bill unless the Mueller legislation is included?”

Schumer never really answered the question:

“Look, I believe…there will be enough of our Republican colleagues who will join us. There’s no reason we shouldn’t add this and avoid a constitutional crisis. And so that is our position. If that doesn’t happen, we will see what happens down the road,” he said.

“We have bipartisan legislation, and a number of Republicans have spoken out. I have spoken to some. People are really concerned about this. Better to avoid a constitutional crisis before it happens.

“And Mitch McConnell said he saw no reason because there’s no interference. With Whitaker, there is every reason to believe there will be interference, based on what Mr. Whitaker has said.”

Schumer and other Democrats say Whitaker’s appointment requires the Senate to “advise and consent.”

In fact, Rep. Jerrold Nadler told another Sunday show that his first oversight priority will be to invite Whitaker — or subpoena him if necessary — to appear before the Judiciary Committee.

Tapper also asked Schumer if House Democrats should file articles of impeachment against Trump – “or is that premature?” he asked.

“I think that the ideal situation, which I hope will happen — I believe our Republican colleagues will join us in making sure it happens — is to allow the Mueller investigation to go forward, to make public what he recommends, and take it from there.

So that’s where I think we should go right now. First step, job one, avoid interference with Mueller. It’s paramount to the rule of law and this country not to become a Third World republic,” Schumer said.