RINOs and DINOs.
For the uninitiated a RINO is a Republican In Name Only. DINO is a Democrat In Name Only. With most words in this field there is no exact definition one persons DINO could be another's far left-wing-nut.
In my book a (R/D)INO is a person who is more interested in being in the winning political party than being in the political party that most closely matches their beliefs and ideals. For example I know a sheriff of a nearby county who is a member of the local [unamed] party not because his beliefs match the [unamed] Party but because in that county they dominate the political scene. In fact his wife told my mother (they are cousins) they were voting for [unnamed] candidate in the presidential election contrary to their local party membership. That is this guy is only a member of the party to get the elected job and the party that most closely matches his beliefs is not able to get him into office.
I was debating resolutions a couple years ago and one of the members of the committee opposed almost every resolution (that year IIRC all we placed in front of the Party passed). These resolutions are boilerplate GOP positions. Why this fellow is a Republican? Perhaps he figures he can get better business connections that way.
Now in terms of Senator Ellis. Why is he not a RINO in my book? Because he generally falls onto the Republican side of issues. I confess I have to look into what this current situation is all about but I am confident in stating Senator Ellis is a good Republican but not necessarily a good team player.