Your point is certainly not without merit. One must also keep in mind, however, that if the GOP loses bunch of Senate seats this fall, just having Chaffee in the "R" column could keep us in the majority. I don't think that will happen, but you never know.
You are right about that. These RINOs are ONLY good if you are slightly above the margin, so they are under pressure to toe the line. As we saw with Jumpin Jim, once they get AT the margin, their power vastly increases.