George Conway, Kellyanne Conway’s husband, warned President Donald Trump’s White House on Friday not to anger GOP Senators Trump could need in the next two years to protect him from impeachment.

When asked about Senate Majority Leader Mitch McConnell’s (R-KY) Thursday evening remarks about how he was “particularly distressed” that Secretary of Defense Jim Mattis was resigning, White House spokesperson Hogan Gidley reportedly told reporters, “I don’t know that Sen. McConnell is concerned about the country.”

Conway said that anyone who “can perform simple arithmetic” would know that this is not a good strategy.

Anyone who reads article I, section 3, clause 6 of the Constitution, and can perform simple arithmetic, can see that this is not a smart strategy. https://t.co/F3DCGcTDz6 — George Conway (@gtconway3d) December 21, 2018

“Anyone who reads article I, section 3, clause 6 of the Constitution, and can perform simple arithmetic, can see that this is not a smart strategy,” Conway tweeted.

Article I, section 3, clause 6 reads:

The Senate shall have the sole Power to try all Impeachments. When sitting for that Purpose, they shall be on Oath or Affirmation. When the President of the United States is tried, the Chief Justice shall preside: And no Person shall be convicted without the Concurrence of two thirds of the Members present.

If the House impeaches Trump, it would take roughly 20 Republican Senators to join with Democrats to convict Trump and remove him from office.

A former Trump aide told Axios on Friday “that the sudden wave of criticism from the Hill over Syria and Mattis should scare the president because he would desperately need these lawmakers’ support during a possible impeachment battle.”

“Once Republican lawmakers start rebuking the president publicly like this over policy, it makes it easier for them to say: ‘It’s not just Mueller or ethics. There are other concerns.’ Then it’s a slippery slope,” the “Trump ally” reportedly added.

On CNN, host John Berman said on Friday that a “Republican staffer on the Hill” said Mattis’s resignation “makes impeachment more likely”

George Conway also ripped Trump on Thursday evening when he tweeted that it spoke volumes that Mattis’s resignation letter did not have a word of praise for President Donald Trump.

“Not a word of praise for Trump,” Conway tweeted. “Speaks volumes.”

He pointed out that the “nicest line” about Trump in Mattis’s letter is “Dear Mr. President.”

Conway added:

No pro forma “it has been a privilege to have worked with you to [something],“ or formulaic “I am proud that we were able to [fill in here]”—or even the usually obligatory “thank you for giving me the opportunity to serve.”

Not a word of praise for Trump. Speaks volumes. https://t.co/WxbVbWLy5s — George Conway (@gtconway3d) December 20, 2018

No pro forma “it has been a privilege to have worked with you to [something],“ or formulaic “I am proud that we were able to [fill in here]”—or even the usually obligatory “thank you for giving me the opportunity to serve.” — George Conway (@gtconway3d) December 20, 2018

The nicest line: “Dear Mr. President.” — George Conway (@gtconway3d) December 20, 2018

In his resignation letter, Mattis wrote that he appreciated “this opportunity to serve the nation and our men and women in uniform.”

“My views on treating allies with respect and also being clear-eyed about both malign actors and strategic competitors are strongly held and informed by over four decades of immersion in these issues. We must do everything possible to advance an international order that is most conducive to our security, prosperity and values, and we are strengthened in this effort by the solidarity of our alliances,” Mattis wrote in his resignation letter. “Because you have the right to a Secretary of Defense whose views are better aligned with yours on these and other subjects, I believe it is right for me to step down from my position.”

Defense Secretary James Mattis has resigned. Here’s the letter: pic.twitter.com/e2PulyXpXZ — Elizabeth McLaughlin (@Elizabeth_McLau) December 20, 2018

Former Director of National Intelligence James Clapper and others made similar remarks. Clapper observed on CNN that Mattis never wrote that it was an honor to serve in Trump’s administration, and he said that was a “compelling omission” in a resignation letter.

“The kind of leadership that causes a dedicated patriot like Jim Mattis to leave should give pause to every American.” – Ret. Gen. Stanley McChrystal to me just now. — Jim Sciutto (@jimsciutto) December 20, 2018