That would have meant really cracking down hard on antiwar and antinuclear protesters during the 1970s and 1980s. And when I say hard I mean the kind of anti-terrorism laws we have today. Things like indicting them for support of terrorism for organizing the kinds of demonstrations that shut down Shoreham and Seabrook nuclear reactors. Things like pulling federal funds from universities that did not require prior military service of all male incoming freshmen while the Vietnam War was going on. Things like requiring all who contract with the US government to fire anyone with a child participating in an antiwar or antinuclear protest. In other words, McCarthy Era style blacklisting.
If the government had made opposition to nuclear energy and weapons tantamount to support for America's enemies and made that support have economic consequences all through the 80s, there would have been no coherent opposition to nuclear power or to Project Nerva or any aspect of the Space Program. The US would be on Mars and probably to the Asteroids, Mercury and perhaps the moons of Jupiter by now. The US would also be as unfree in the 70s and 80s as it is today.