It's important to view neoconservatism as a pillar of the "three-legged stool" comprising the fusionism first-espoused by William F. Buckley and manifested in Goldwater campaign. This ideological marriage remained on the fringe of the Overton Window until various elements (e.g. Vietnam for Greatest Generation-era Democrats and their children who served, the desegrationist movement for Dukes of Hazzardesque Dixiecrats) drove their various wedges into the New Deal Coalition. Then stagflation caused the minarchist leg to re-appear as the AFL-CIO's rank-and-file defected (at least temporarily) into the apocryphal Northern Reagan Democrat mold.
Now whole time religious fundamentalists such as Phyllis a55fly Schafly and Moral Majority types created a new cultural framework for a Christian Right seething over Warren/Burger (no pun intended) court rulings and pretty much about everything the Sexual Revolution and second-wave feminism stood for. This Dominionist impulse galvanized the Southern Strategy already livid over the aforementioned racial grievances. I'll leave the details to those who know more what's up w/those subjects, however it's not hard to understand why the people who Satanic Panicked over Dungeons and Dragons would hate those godless commies.
The Cold Warrior plank regained steam both due to the Soviet Invasion of Afghanistan and legitimate concerns of the Warsaw Pact surpassing NATO's capabilities. The Warsaw Pact arguably held the upper hand by 1977 as it not only augmented its long standing conventional forces advantage but also at least equaled NATO's nuclear deterrent via its SS-20 missiles. Reagan himself long desired nuclear abolition and highlighted opposing détente due to atomic fears in his 1976 RNC speech. The Iranian Hostage Crisis proved a final straw for Americans who'd already felt humiliated over Vietnam, the Gas Crunch, and everything in between. Reagan seized the moment over a Carter campaign already hamstrung by a labor-backed Kennedy primary challenge, and the New Right finally had one of the own calling the shots.
From there Reagan's various actions as executive such as massive tax cuts, firing the air traffic controllers, cutting nurturing the military industrial-complex in hopes of driving the USSR bankrupt (which tbh did help get the nuclear treaties done), iinadvertently jump-starting crack epidemic via his perversion the Monroe Doctrine, deriding AIDS as the "gay plague", perpetuating a fossil fuels-dependent economy, founding the mass incarceration state, and reprising old Atwater racial tropes as electorally needed codified neoconservatism as an ideology. Bush Sr. ratcheted up the cultural dialectic. He escalated the disastrous War On Drugs and declared we needed to be more like the Waltons and less like the Simpsons. For their part social liberals mostly capitulated into law-and-order rhetoric in face of the violent crime wave; After all, the Congressional Black Caucus and most Black Americans supported the 1994 Crime Bill. They simply had the wrong phucking solutions.
Evangelicals came to the GOP's center stage through Gingrich's '94 revolution sweeping across the South. Neoconservative think tanks such as the Heritage Foundation drafted ill-advised policy prescriptions such as DOMA and welfare reform passed a Clinton administration clawing for any scrap of political capital. You also saw the "us vs. them" mentality during the 90s government shutdown which both paved the way for Karl Rove's "majority of majority party" tactics and the Tea Party-infused Obama era budget fights. By 2000 the New Right wrestled control from endangered Rockefeller Republicans as well as warded off the Buchananite impulse. Bush Jr. dominated the South and Plains in the primary via consolidating the conservative vote against McCain, and after that whole Florida thing the think tank-drafted (you may be noticing a theme here) Project for a New American Century got its turn at the wheel.
I won't spend too much time writing about the Bush Jr.'s implementation of the 3-legged stool (e.g. squandering the budget on tax cuts, passing bankruptcy laws which really blew during the Great Recession, the litigated ad nauseam foreign policy unilateralism, preying on post-9/11 fears to encroach on privacy rights, letting the Assault Weapons Ban expire, codifying the idiocy of unfunded mandates through NCLB, etc. etc.) because its failures are still relatively fresh with most. By 2008 the three-legged stool had thoroughly splintered and turned its sights more towards state-level control via ALEC and other Koch-funded enterprises which flourished after Citizens United.
Tl;dr: It's a gross oversimplification to define "neoconservatism" as an interventionist foreign policy impulse born out of Red Scare fears. Rather, it is a facet of the fusionism which emerged as a reaction towards the postwar economic consensus then absorbed traditionalist grievances over the countless sociocultural upheavals during the 60s and since. Overall, the ideology glorified hubris through divinely-inspired American exceptionalism, consistently generate(d) some of the worst public policy failures in postwar history, and caused mass wealth concentration and environmental challenges which we are still struggling with to this day. One must understand its deep sociopolitical roots to fully grasp how phucking lemon-headed these people are.
I prefer a more restrictive definition of neoconservative then one that encompasses the entirety of Reaganite Conservatism, because doing so is itself an oversimplification of the nuances and differences on the right with regards to foreign policy.
Not everyone this side of Ron Paul, is a neocon.
Most rank and file Republicans don't like the Pauls. I talk to people. As you are seeing in current polling, there are still themes that are keeping the Republican Party together, such as Race Relations, Sexuality/Spirituality, and TAX CUTS. On the other hand, they are as incoherent as ever on FP (though unilateralism is still the name of the game). With the discrediting of the PNAC folks, the neoconservatives are just one competing special interest out of many (instead of the one that is running the show, like the Religious Right is currently).
Which make sense with how the sands are shifting. Places with a strong MIC presence are beginning to soften up for Republicans (look at Colorado Springs), but other places that are relatively dovish but somewhat conservative are trending rapidly in their direction (Iowa, Wisconsin). We are basically seeing the Republican Party disown some liberal parts of Neoconservatism (Globalism, Interventionalism) and keeping the more aggressive parts (Unilateralism, a belief in Total War/Gitmo situations). It is actually proving to work for Republicans as they still are mobilizing the Religious Right even more so than ever, but also now turning out Nationalists in big numbers when they in the past would not vote or vote for someone like Obama because he supported a pet cause of theirs.
