PORTLAND, Maine—Sen. Elizabeth Warren (D., Mass.) campaigned Saturday alongside Graham Platner, the left-wing candidate in the Maine Democratic Senate primary who has praised Hamas and until recently sported a tattoo of a Nazi symbol. Warren said Platner "has the values" to serve in the upper chamber and would bring "accountability" to Washington, D.C. Platner "is a man who not only has the values, but a man who believes in accountability, and we need a little accountability coming out of