I disagree with most tenets of conservative thought, but even those I consider demonstrably false or even morally bankrupt I feel I understand. Conservatives oppose subsidizing health insurance because they consider health care a matter of personal responsibility, or just deem covering the uninsured a very low fiscal priority. They think climate change is overblown, or completely fake, or possibly real but not worth the cost of addressing. Etc.

But there's one aspect of conservatism I simply don't understand, which is its approach to many forms of government spending. Conservatives believe, in general, that many forms of government spending are wasteful, a belief shared by large segments of the public. This I understand. the problem is that when conservatives come into contact with actually existing budgets, they wind up implementing some pretty horrific policies -- not merely horrific to liberals, but horrific to (at least my understanding of) most conservative's priorities.

For instance, conservative Republicans in Congress are slashing the transportation budget:

The next flash point in the debate over the nation’s will to live within its means may emerge this week as House Republicans present a long-term transportation bill expected to cut funding for highways and mass transit by almost one third. ...
“According to numerous experts, including the American Society of Civil Engineers, the U.S. needs to invest an additional $1 trillion beyond current levels in the next 10 years just to maintain a state of good repair and meet demand,” the letter said.
Two major studies in the past year have urged increased spending to revitalize the nation’s aging infrastructure. The Urban Land Institute concluded that the United States needed to invest $2 trillion to rebuild roads, bridges, water lines, sewage systems and dams that are reaching the end of their planned life cycles.
Without that investment, the institute warned that the United States would fall dramatically behind much of the world in providing transportation networks needed to remain competitive in the global marketplace.
That report buttressed the findings last fall by a panel of 80 experts led by former transportation secretaries Norman Y. Mineta and Samuel K. Skinner. The panel concluded that as much as $262 billion a year must be spent on U.S. highways, rail networks and air transportation systems.

So all the major experts conclude the transportation infrastructure requires a major funding increase in order to maintain economic competitiveness, but the Republicans instead plan to pass a huge funding cut. Again, that in and of itself does not shock me. There is no shortage of policy areas where the conservative movement takes a position dramatically at odds with the academic/expert consensus. What's confusing to me here is that I don't know what the conservative movement position is. Do they think we're overinvested in infrastructure? That if we reduce government involvement, the private sector will step in? Or that the economic benefits of maintaining our physical infrastructure -- or, more realistically, falling behind at a slower pace -- are simply smaller than the economic benefits of keeping taxes low?

Likewise, state and municipal budgets starved of revenue have slashed funding for extended learning time:

After several years of state and local budget cuts, thousands of school districts across the nation are gutting summer-school programs, cramming classes into four-day weeks or lopping days off the school year, even though virtually everyone involved in education agrees that American students need more instruction time.

Now, this isn't always a direct conservative policy initiative -- many of these cuts are imposed by Democratic-controlled governments. But it is a policy initiative directly created by conservative policies, which have staunchly opposed any federal aid to state and local governments, or any tax increases at the state level, to prevent cuts like this. Again, I'd like to understand the conservative position here. Do they contest the extensive evidence showing that extended learning time is a highly efficient intervention? Do they agree it's highly efficient but think it's simply less efficient than the economic benefits of low taxes?

There are many instances of these cuts going on. The domestic discretionary budget has been constant over the last decade:

Republicans are seeking to implement very large cuts in the domestic discretionary budget category while minimizing defense cuts and fighting tax increases to the death. The House GOP Budget proposes to, over time, virtually zero out all funding for domestic discretionary spending, which obviously even Republicans would never actually implement, but it does signal the movement's disposition toward this category. I'd dismiss it as a simple failure to understand these programs in any detail. But we're already at the point of implementing just the beginning steps of this vision, and it entails things like a one-third cut in the federal transportation budget. I'd really like a conservative to explain the movement's analysis of this. Libertarians, of course, are free to jump in, too.