Ever hear of "Yellow Dog Democrats"?
My grandfather, who turns 95 this year, is one. A Yellow Dog Democrat is someone who would just as soon vote for a yellow dog as ever vote for a Republican.
Another version from Yellowdogs.org dates back to 1928 where some Alabamians stated, "I'd vote for a yellow dog if he ran on the Democratic ticket!"
But then, I guess that's somehow different than when Republicans express party loyalty.