The Blue Dogs derive their name from the artwork of a Cajun painter, George Rodrigue, well known in Louisiana for his series of paintings featuring an unusual blue dog. The fledgling members of what became the Blue Dog Coalition used to meet regularly in the offices of then-Democrats Rep. Billy Tauzin and Rep. Jimmy Hayes of Louisiana. Tauzin has since switched to the Republican party and Hayes was defeated in a run for the Senate. The Louisiana representatives had Rodrigue’s blue dog paintings displayed on the walls of their offices, and these provided the inspiration for the coalition’s name. One of the Blue Dogs, Rep. John Tanner from Tennessee, maintains that Blue Dogs are simply “yellow dogs that have been choked by extremes in both political parties to the point they have turned blue.”

Blue Dog Democrats are an actual voting coalition made up of Members of Congress, whereas Yellow Dog Democrat is an expression -- it describes a certain kind of voter. Nor are Blue Dogs ideological relatives of the "Yellow Dogs" of the South, even though they have similar names.

Quoted:
(snip)Candidate #2, the Democrat, was an old yellow, broken-legged dog, mangy, blind in one eye. It spent it's days lying on the porch, farting, biting strangers, and licking it's own private parts.

A "yellow dog" democrat will always vote for candidate #2 because of party affiliation.

BTW, is it just me, or is candidate #2 reminiscent of Ted Kennedy?