BOSTON (AP) — An aide to former Gov. Mitt Romney is the latest Republican stepping up to challenge Democratic U.S. Sen. Elizabeth Warren. Beth Lindstrom said in a video message posted Monday that she was "all in" for the 2018 race and promised a more formal rollout of her campaign in the fall. Lindstrom, describing herself as an "independent-minded Republican," said there was plenty of blame to go around for the inaction on major issues in Washington. "Don't get me wrong.