Photo: Caroline Brehman/CQ-Roll Call, Inc via Getty Images

Sen. Susan Collins (R-Maine) announced Wednesday that she'll seek re-election for a fifth term in 2020, AP reports.

Why it matters: The campaign is projected to be one of the most expensive races in Maine history, as Democrats believe the centrist's seat is vulnerable.

  • She said in an email to supporters that her "bipartisan commonsense approach" will be necessary in an era of bitter partisanship.
  • Collins also faces a dramatic decision in the coming weeks on whether to vote to convict President Trump in a potential impeachment trial in the Senate.

What she's saying: Collins did not hint at how she might vote in her announcement email, but she did acknowledge the nation's divisive politics.

  • "To say that these are difficult and contentious times is most certainly an understatement. But our country has confronted much more challenging times in our history."
  • "The fundamental question I had to ask myself in making my decision was this: In today’s polarized political environment, is there still a role for a centrist who believes in getting things done through compromise, collegiality, and bipartisanship? I have concluded that the answer to this question is 'yes.'"

The state of play: The four Democrats currently vying for her seat include Maine House Speaker Sara Gideon, activist Betsy Sweet, attorney Bre Kidman and former Google executive Ross LaJeunesse.

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McMaster: Trump's peaceful transition comments are a "gift to our adversaries"

President Trump's refusal to commit to a peaceful transfer of power if he loses November's presidential election is a "gift to our adversaries," Trump's former national security adviser H.R. McMaster said Sunday.

The big picture: McMaster, a retired three-star general, said that the American people must understand that the military will have "no role" in a presidential transition and that it's "irresponsible" to even talk about it as a possibility.

Trump says Supreme Court ending Obamacare would be "a big WIN"

Photo: Spencer Platt/Getty Images

President Trump on Sunday tweeted that the Supreme Court invalidating the Affordable Care Act would be "a big WIN for the USA!"

Why it matters: Democrats have argued that confirming a Trump-appointed justice to the Supreme Court would put the Affordable Care Act, which protects pre-existing conditions, in jeopardy. Trump's Supreme Court pick, Amy Coney Barrett, has written that she disagreed with Chief Justice John Roberts when he ruled to uphold the law.

Trump sees court fight as virus respite

Spotted at Trump's rally last night at Harrisburg International Airport in Middletown, Pa. Photo: Joshua Roberts/Reuters

At a rally in Pennsylvania last night, President Trump basked in adulation for Judge Amy Coney Barrett and said, "She should be running for president!"

Why it matters: She might as well be. The Trump campaign is thrilled to be talking about something besides the president's handling of COVID, and it's going all-in to amp up the court conversation.