He is the electoral anomaly gliding through the halls of Congress, trailed by reporters and turning up on television to talk about a path forward, all the while feigning nonchalance over the outsize clout he has over whether senior citizens on Medicare get dental coverage and whether the federal government will get behind poor kids going to preschool. Sen. Joe Manchin III is the Democrat representing the red state of West Virginia. But he isn’t so much a blue politician as he is a gray one. These days, he is the gray grump who has told his political colleagues that he will commit to spending $1.5 trillion on President Biden’s “Build Back Better” plan and not the $3.5 trillion that the majority of Democrats support.