So why not look for a candidate that appeals to all three? Because the several groups are now in contention with each other. Social conservatives don’t like seeing people abandoned essentially in economic terms and want to protect SS and welfare programs for reasonable use in their view. Business people have had there way for the last 20 years hammering the working class over and over such that average after-tax worker individual income adjusted for inflation is lower than it was in 1973. The military conservatives are not getting their way with guys like McCain in charge and you can just look at the VA fiascos exposed this year for proof of that if you need it. He also short-circuited several efforts to trace/free POWs in the 1980s as well.
And see, that, right there, is the problem. Reagan was, first and foremost, a foreign policy conservative. Reagan claimed to be an economic conservative and a social conservative. However, one could easily say that Clinton was more economically conservative than Reagan, as Clinton, with a GOP Congress, eliminated the general welfare program, balanced the budget, and repealed the Glass/Stegall Act. And Reagan really wasn’t deeply religious, either. Ford and Carter were both much more religious than Reagan; Reagan just understood the power of the “Values Voters” and was able to get them to back him by adopting the main objectives that they had at the time - being against abortion and Communism. Honestly, the reason Reagan was able to pull his coalition together so well was due to the fact that he was a polished actor and was able to convince people that he really believed what he said - whether he believed it or not.
GHW Bush was also a foreign policy conservative - in fact, foreign policy was his main area of expertise (I actually believe he would have made a better Secratary of State than President), and he even had a diplomatic award named after him. But he knew little about economics, and when re-election came around, appeared astounded by things that everyday Americans had seen for several years on a daily basis (such as scanners at check-outs).
GW Bush was a religious conservative. There’s a reason why Dems created a map of the US after the 2004 elections which dubbed the states that voted for GW Bush “Jesus-land”. Both of GW Bush’s victories were extremely narrow, and Dems are still fuming over Florida from 2000 and Ohio from 2004.
The main losers during this time? Dole and Romney - both primarily economic conservatives, and McCain. I’m keeping McCain out of this, because, in 2008, the GOP could have nominated Jesus Himself and the Dems could have nominated a rock, and the Dems would have won. But, honestly, GOPers who are primarily economic conservatives seem to have a hard time winning. Why? Well, for one, religious conservatives might not believe that economic conservatives actually care about their causes. That may very well be the case, as even many GOP governors seem, well, kind of annoyed when religious conservatives try to push the so-called “culture wars”. And Romney famously didn’t adopt a pro-life stance until 2006/2007, when he announced his first candidacy for President. IIRC, as governor of MA, Romney had a pro-“choice” view. As for Bob Dole, he really couldn’t differentiate himself from Clinton - who had ended up doing just about everything the economic conservatives wanted, anyway.
It seems to me that the best option for the GOP would be, first and foremost, someone who is conservative on foreign policy. Not an all-out war hawk, mind you (Reagan was no war hawk), but at the same time, able to follow through on any threats and/or promises made. Secondly, conservative on social issues, at least enough so that social voters don’t feel that only “lip service” is being performed. Show up to the March for Life and the March for Marraige. Encourage Congress to pass an amendment to the Constitution affirming life in the womb. Ask for PP to be taken out of the federal budget. I think it’s suffices to say, that at the Presidential level, conservatism on economic policy seems to be the least important of the three to people who might consider voting for a GOP Prez.