In this March 14, 2019, file photo, Sen. Susan Collins, R-Maine, smiles at the Capitol in Washington, after the Senate passed a resolution to terminate President Trump's declaration of an emergency at the Southern border. Maine's Democrat Speaker of the House Sara Gideon announced Monday, June 24, 2019, that she will challenge longtime Collins in the 2020 election. (AP Photo/J. Scott Applewhite, File)
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