AUGUSTA — A physician from Washington County announced her intentions Monday to challenge U.S. Sen. Susan Collins in 2020. Dr. Cathleen London of Milbridge, a member of the Maine Democratic State Committee, said she is launching her campaign so early “because health care and the Supreme Court cannot wait until another full election cycle.” London specifically criticized Collins – a moderate Republican frequently regarded as a swing vote – for saying that she would not use the Roe v.