Photo: Chip Somodevilla/Getty Images

Another reason this is a historic week — and what President Trump should really worry about — is that lots of different Republicans have been turning on him over different topics.

Why it matters: A former Trump aide who asked to be described as "a Trump ally" told Axios 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."

Catch up quick: In an unusually harsh statement, Senate Majority Leader Mitch McConnell said he was "distressed" about Mattis' departure: "It is regrettable that the president must now choose a new Secretary of Defense. But I urge him to select a leader who shares Secretary Mattis's ... principles."

  • Sen. Ben Sasse (R-Neb.) said after the Mattis announcement: "This is a sad day for America."

Bloomberg columnist Eli Lake: "Donald Trump may not know it yet, but his presidency is collapsing."

  • "As long as [Mattis] served the president, reluctant Republicans could point to the Pentagon and say: If Mattis supports Trump, then so do I. They can no longer do that."

Be smart: We talked all day yesterday with Republican officials, operatives and advisers who are truly scared for America.

  • But it's telling that few have the courage to say it publicly.

What to watch: There’s a working assumption inside the White House that Trump will be impeached by the House. He would then need a rock-solid base of 34 Republican senators to refuse to remove him from office (which takes 67 votes).

  • So nothing matters more to Trump than keeping his base happy and loyal. 

Go deeper: As a sign of the mood inside, officials at both ends of Pennsylvania Avenue tell us that Trump is complaining about his incoming chief of staff, Mick Mulvaney, in conversations inside the West Wing and with Capitol Hill.

  • Trump asked one trusted adviser: "Did you know [Mulvaney] called me 'a terrible human being'" back during the campaign?

Go deeper

Updated 6 mins ago - Science

Hurricane Isaias makes landfall in North Carolina

People walk through floodwaters on Ocean Blvd. in Myrtle Beach, South Carolina, on Monday. Photo: Sean Rayford/Getty Images

Hurricane Isaias made landfall as a Category 1 storm near Ocean Isle Beach in southern North Carolina at 11:10 p.m. ET Monday, packing maximum sustained winds of 85 mph, per the National Hurricane Center (NHC).

What's happening: Hurricane conditions were spreading onto the coast of eastern South Carolina and southeastern N.C., the NHC said in an 11 p.m. update. Ocean Isle Beach Mayor Debbie Smith told WECT News the eye of the storm triggered "a series of fires at homes" and "a lot of flooding." Fire authorities confirmed they were responding to "multiple structure fires in the area."

Updated 1 hour ago - Politics & Policy

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 12:30 a.m. ET: 18,224,253 — Total deaths: 692,679 — Total recoveries — 10,865,548Map.
  2. U.S.: Total confirmed cases as of 12:30 a.m. ET: 4,713,500 — Total deaths: 155,401 — Total recoveries: 1,513,446 — Total tests: 57,543,852Map.
  3. Politics: White House will require staff to undergo randomized coronavirus testing — Pelosi says Birx "enabled" Trump on misinformation.
  4. Sports: 13 members of St. Louis Cardinals test positive, prompting MLB to cancel Tigers series — Former FDA chief says MLB outbreaks should be warning sign for schools.
  5. 1 🎥 thing: "Tenet" may be the first major film to get a global pandemic release.

Exclusive: Trump declines to praise John Lewis, citing inauguration snub

President Trump dismissed the legacy of the late Rep. John Lewis in an interview with “Axios on HBO,” saying only that Lewis made a “big mistake” by not coming to his inauguration.

The big picture: Trump's comments were a glaring contrast with the praise Republicans and Democrats showered upon Lewis this week, and a default to personal grudges during a week of mourning for a civil rights hero.