To be right wing is to be connected to the realities of human nature and social organization. To be left wing is to reject these realities in favor of an idealized version of what society should look like. People can embrace the right on abstract principle, but the incentives that drive organizations and classes of people to embrace the right are ultimately practical (generally that they sense that the left wishes to do them harm).
The military and big business are two entities often thought to be right-wing strongholds, and which historically were (to a certain extent). The reasons for this are obvious; armies and corporations must both deal with realities not amenable to ideological denunciation; they must both use means not in accord with the left’s idealism. When it was still possible (or at least seemed possible) for the left to be defeated, it was in the interests of these entities to secure right-wing victory, and many of their members acted to that end. They were repaid with the left’s usual existential hostility.
The important thing to understand is that both of these reasonable and pragmatic entities have made the reasonable and pragmatic judgment that their interests are better served by joining the left. Thus the military roots out “racism” and “extremism” from its ranks, and embraces every social experiment imposed on it; Big business proudly endorses BLM and sexual perversion. As a strategy for avoiding the left’s ire, this has worked. Enraged hippies are no longer spitting on the troops, there are no (serious) attempts to attack military funding, there are no (serious) attempts to nationalize industries or subject them to punitive taxation. The military and big business have secured their place in the sun. Business interests have even gotten perks they wouldn’t have (and didn’t have) in saner times, e.g. large numbers of women and low-skill foreigners in the workforce, license to monetize filth, and freedom to operate seven days a week.
This situation is only going to become more pronounced. As I write, the military is planning a purge of right-wingers in its ranks. Business interests are severing their legacy patronage relationships with the GOP (which is itself desperate punching right). The left’s continued ascendancy ensures that no one who matters has any pragmatic reason to have anything to do with the right. There is no mechanism that will halt this process.
Which brings me back to the point expressed in the title. In order to defeat the left, you need powerful institutions that seriously oppose the left. Such institutions do not exist, will not be permitted to exist, and would be co-opted if one did pop into existence. Any path to right-wing victory that was possible in years past (if it was even realistically possible in the first place) is now closed off.