"RINO, of course, refers to Republicans In Name Only and is the pejorative term used against those who fail to march in lockstep with the so-called conservative base. I used “so-called” because, though the hard-right faction of the party tends to be viewed as The Base, this isn’t necessarily so. My guess is there are now more RINOs than those who, though evangelical in their zeal, are poison to their party’s ability to win national elections."- [1]

A Republican In Name Only or abbreviated as RINO is a member of the Republican Party but doesn't have conservative beliefs. RINO is apparently an insult. [2]

Mainstream Americans think RINO's are quite a bit saner than the right wing of the Republican Party.

Republicans Accused of Being RINOs

Rockfeller Republicans

Rockfeller Republicans are a term more likely used in the fifties and sixties for more moderate and liberal Republicans. This is used much less today.

See also