They believe the "proper" stewards of society are the wealthy. In order for the wealthy to make the best of things, they need that money, so low taxes.
But the wealthy need something else, a desperate working class that will do anything the wealthy says just so they can eat and have some chance at things like decent healthcare. One of their favorite refrains is "nobody wants to work anymore", and in part they blame government assistance for this perceived lack of workers or workers that are so uppity as to demand a living wage.
Of course desperate people can do something other than nicely do the things the wealthy tell them to. So that's where "law and order" principles come in. Make a big authoritarian police force to discourage the more dangerous path that mass desperation can cause.
That's how the US Civil War happened, but frequently a national Civil War does not have such clear boundaries and sides. See Syria for a very messy conflict where about the only thing defining one 'side' was 'not Assad' and very little agreement other than that.
Civil war would be the worst possible outcome to be sure, but a messy situation can just as easily feed a civil war.