Actually that's far from original. Obtaining great victories for the advancement of your power unit is a great way to take control at a very hearts-and-minds level and memetically and without further effort brand all opposition or even serious criticism as traitorous to the cause of the power unit.

Sure, but I meant something more specific in FDR's case. Basically, any post-WW2 American right-winger (by which I mean someone whose values and beliefs are roughly in line with what's commonly understood as "right-wing" in the American context) is in a position where his values and beliefs would naturally lead him to a strongly negative overall view of FDR -- except for FDR's role as a great war leader, where his patriotism will lead him to feel like it would be treasonably unpatriotic to condemn FDR and examine critically the whole mythical legacy of WW2. This has indeed been a source of major cognitive dissonance for the entire post-WW2 American right, and one of the reasons why it could never come up with anything resembling a coherent and practical ideology. (The previously discussed 1950s era McCarthyists being one example.)

Of course, there have been some right-wingers who have bit the bullet, condemned FDR, and went on to attack the sacred myth of his legacy head-on. However, these have never been more than a marginal phenomenon, and in fact, such tendencies have always been a surefire way to get oneself ostracized from the respectable mainstream of the American conservatism.

You mean to say it wasn't even before that, or that it is in any way exclusive to American society, as opposed to every society in the planet save for very specific corners of the Internet?

The key difference is that in the pre-New Deal American society, the norms to which one was supposed to conform were determined at the local level. The enforcement of conformity was indeed often quite severe and unforgiving, and it ranged anywhere from just shunning to extralegal retaliation by the local law enforcement to downright mob violence, up to and including lynching. However, it was completely local in character, and one always had the option of moving to a different town or state where the local opinion would be more to one's liking.

The New Deal was an innovation in that it established the bureaucratic and legal infrastructure for ideological enforcement on the nation-wide scale, not just directly through the vastly expanded federal government, but also through its myriad tentacles that have since then grabbed just about every institution of organized society, both state and private. Of course, this control has been much gentler than the previous localism, and, thanks to the enormous wealth it commands, this system has been able to afford using carrots more than sticks. However, it has also led to an utterly dreadful intellectual uniformity compared to what had existed before.

(To be precise, there had been some precedents before that, but they were all short and happened during exceptional wartime situations. The New Deal however established it as a permanent and regular feature.)