Not so Fitzgerald.  Remember the Republican senator from Vermont who swung the majority back to the Democrats when he turned his back on the Republicans and turned independent?  Other moderate thinkers can also be found at the US Supreme Court level too, i.e. Justice Roberts voted in favor of Obama Care, and Justice Kennedy voted in favor of same-sex marriage.  I'd say these men have a spine, just not the type of weak spine you may be accustom to.