So depending on who you ask you get different answers because there are a few different groups working together, and at least half of them are using the other half.

So originally you had two groups. The first group for lack of a better term were the 1%, their goal is to destroy the government and install oligarchs that will allow them to write the laws to be whatever is most beneficial to them and allow them to more efficiently funnel all the money into their pockets. Their first order of business was to reduce or eliminate their taxes, followed by eliminating regulations.

In order to convince everyone else that they should be allowed to do these self serving things that harm everybody else they came up with the lie of trickledown economics and pushed that message hard using Reagan.

That brings us to the second original group which was the economic conservatives that were concerned by the US running a deficit for so long. They didn't want to raise taxes so they decided the problem was too much government spending and/or inefficient government spending, and that if we just cut back things here and there or optimized spending to be less wasteful it would fix everything. The lie of trickledown economics was crafted to appease this group with the fake promise that government revenue could be increased by reducing taxes on the rich.

Fast forward a little ways and the first group is still around with the same policies and goals, but now the goal posts have moved for the second group. The first group has successfully convinced the second group that the government is broken and that there are large groups (mostly minorities and the poor) that are running some kind of con and stealing money from the government (the irony of course being that it's almost entirely the first group doing exactly that). They've been convinced that government provided services are actually the problem and need to be eliminated.

They spent a decade or so trying to convince everyone that government programs should be shut down using various arguments, but because everyone else aren't morons they were largely ignored. Ultimately they arrived at their current plan which is to just keep cutting taxes to the point where the government can't afford to function and is forced to shut down.

So the current situation is actually the goal, they want the government to essentially go bankrupt, the first group because then there's no one to tell them things like that they're not allowed to dump toxic waste into everyone's water supply or that they have to treat their workers like actual humans and not cattle, and the second group because they're living in a delusion.