Sen. Martha McSally, R-Ariz., said Tuesday that if Joe Biden wins the presidential race and Democrats retake control of both houses of Congress, Puerto Rico and Washington, D.C., would gain statehood.

McSally warned that if Democrats win full control of Washington, they will vote to give Puerto Rico and D.C. full voting rights on Capitol Hill via statehood, making it impossible for Republicans to ever regain control.

“They're going to make D.C. and Puerto Rico a state and get four new Democrat Senators. We'd never get the Senate back again,” the Arizona Republican said.

“They are going to ram through the most radical left agenda we’ve seen in history,” McSally told MSNBC’s Vaughn Hillyard.

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In June, the House passed a D.C. statehood bill for the first time, but the bill is presumed dead on arrival in the current Republican-controlled Senate. If D.C. were to become the 51st state, it would gain two voting Senators and one voting House member to represent its 700,000 population. D.C. has voted Democrat in the presidential election ever since it gained three Electoral College votes in 1961.

Puerto Rico’s politics are harder to gauge -- its two major political parties break over the island’s political status -- whether to seek statehood or whether to remain a territory -- rather than the U.S.-based Republican-Democrat divide. Still, a November 2018 poll found that the mainland favored Democrats 70 percent to 27 percent in the midterm elections.

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McSally was appointed to fill the open Senate seat of the late Sen. John McCain in 2018 after losing to Democrat Sen. Kyrsten Sinema. She is facing off to keep her seat against Democrat Mark Kelly in 2020. She said the Democrats’ “radical left agenda” is “so out of touch with Arizonans” that her opponent is “hiding and trying to pretend he’s not a Democrat.”

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McSally’s seat is one of the Democrats’ top targets this year, and she is among the most vulnerable of GOP senators up for reelection. A new Arizona Public Opinion Pulse survey showed Kelly leading McSally 48 to 43 percent. Kelly maintains a significant lead with Arizona’s independent voters, of which the state has 1.2 million. The survey shows Kelly garnering 47 percent of independent voters to McSally’s 34 percent.