Michael Tomasky: Robert Byrd

Robert Byrd has died. The West Virginian is the longest-serving senator in United States history, having been elected to a staggering nine terms, the last one in 2006, and he served more than half a century in the body.

Democratic defenders of Byrd point to highlights such as his outspoken opposition to the Iraq war and his support for the Panama Canal treaty in the late 1970s as evidence of his progressive bent. Detractors point to his opposition to civil rights in 1964 and his brief...