You have to remember two things.
1. Sunbelt conservatives come from a region where Federal spending was a major growth engine from military bases to the TVA to agricultural subsidies to the interstate highway system.
2. Sunbelt conservatives were New Deal Democrats two generations ago. They were never Old Guard Republican thin lipped "the business of America is business" types.
Did you think that through before you wrote it? LBJ did not run for reelection because he could not successfully prosecute the Vietnam war. No comparison.
I've felt that in a gut way for a while, but hoped I was wrong. The painful similarities between Rumsfeld and McNamara have something to do with it.
Bush is one third or one half a conservative -- depending how you break it down. He's not a small government, low spending conservative, and he also doesn't look much like a traditional conservative on foreign policy, but in some real ways he is social/religious conservative. To that you could add his low-tax pro-growth, pro-business outlook, which probably qualifies as more conservative than liberal, though both budget cutters and free marketeers would disagree.
But across the board, up and down the line conservatives are a smaller a part of the population than many people think. It's also not clear just what the "real thing" would be. Politicians come up with a mix: they stand firm on the things they think are important, and avoid conflicts on other, less important matters. Bush's mix hasn't been as appealing as, say Ronald Reagan's, because he let go of some important concerns. For example, it wouldn't have hurt President Bush or the country any, if he used his veto power once in a while, or to stand up for our immigration laws, but on right to life issues, he's been quite solid.
The Bush years give the lie to one common idea about our politics: that elections pit the big government blue states against the small government red states. There's certainly some truth in that way of thinking: the blue states are larger, more urban, and more crowded, so they support all the big government programs that urban areas want. They're also the center of secular liberalism today. And the red states are smaller and more rural. They don't go in for the liberalism of the blue states.
But the blue states are more divided into competing and conflicting groups. It's hard to reach a consensus on things there, and they're often already financially overextended. By contrast, there's more community in the red states, more agreement about things, and more religiously-inspired social concern. So you'll find some red state leaders who aren't as opposed to big government as, say Robert Taft or Barry Goldwater was. They don't have any use for the ideological liberalism of the Democrat strongholds, but they accept large-scale government programs.
Conflicts between secular and religious, liberal and conservative are sharply defined on the national scene, but disputes over this or that program are a lot blurrier in local politics, so you do find politicians who are very strongly religious and and socially conservative, without following the Goldwater line on big government.