Right wingers seem to be all over the place ideologically. The coalition includes country clubbers who just want to keep their taxes down and swarthy people out of their neighborhoods (except their servants) and Christian Dominionists who want to establish an American Taliban of sorts. Then there's them as are motivated almost entirely by race and ethnic hatred. Moreover, there's a slew of just plain authoritarians who can't stand it when anyone has any choices in life they they themselves wouldn't make (or claim that they wouldn't make). What holds all this together? Stupidity on the part of the right wing electorate and a shameless desire for power at any cost by the right wing leadership. Otherwise, the coalition makes no sense, and you'd have some Republican politicians who at least pretended to give a rat's ass about the well being of the country.
That's also why it's easier for the right to keep its focus on a set of insane talking points and to be disciplined. There aren't any real differences of opinion among them, just competition for place within the Party. They don't have to think about policy or the common good, because that's irrelevant to them. In fact, the shittier things are, the better for them since they rely so heavily on fear and anxiety.
The Democrats, while not being saints, actually seem to care about policy and to have genuine good faith differences among themselves. This makes them look "undisciplined" compared to the GOP with its officials marching in lockstep all the time. The left sometimes wishes that its party were more ruthless and under tighter control, but that would be a monstrous tragedy and the end of even the appearance of democracy. If we had two parties engaged in a no holds barred power grab, they would destroy the country. As it is, the GOP may be able to destroy the country all by itself.