Mike McCormack is able to win re-election in 1980 and solidify the Pro-Fusion lobbying force in Congress he was in the process of building IOTL that had already been able to pass the Magnetic Fusion Energy Engineering Act of 1980. With a strong force to push for Fusion, it's likely you'd see the Center for Fusion Engineering be created while projects like Princeton’s Tokamak Fusion Test Reactor (TFTR) and Lawrence Livermore Laboratory’s Mirror Fusion Test Reactor get a chance to actually operate, instead of shut down on the day they were supposed in the example of the latter. Others, like Oak Ridge's Elmo Bumpy Torus preliminary design for a 1200 MW magnetic fusion power plant would actually get built, same for Princeton's Compact Ignition Tokamak (CIT). It's important to note that the Reagan Administration wasn't opposed at all to Nuclear Fusion, indeed setting high funding for it during the first term, but said funding began to languish without a unified bloc in Congress to support the costs and
especially so with declining oil prices in the second half of the decade. if McCormack had been able to stay and continue his work, combined with the openness of Reagan to said work, I think there would've been more than sufficient political will to see support for the costs continue and thus keep the United States on track for a working reactor by 2000. Such was stipulated by the previously mentioned legislation, which used
1976 projections by the ERDA to establish its time frame. By ATL 2019, Nuclear Fusion would likely be entering commercialization if not already a few years into such, if the timeline presented by ITER is anything to go by.
Another way to help would be to screw over oil. Have Saddam be successfully assassinate at Dujail in 1982 by Kurdish fighters. In the event of his death, given the purges he had previously conducted, it's likely Ad-Douri or Khairallah Talfah would take power. Both have their issues, but both would definitely being more willing to let the Iraqi Army engage in offensives and counter-offensives against the Iranians. Saddam IOTL was pretty reluctant for many years to allow such, resulting in the relatively static war that dominated much of that conflict. With a more aggressive Iraqi leadership from 1982, it's possible the conflict could end much sooner; let's say 1985 and with the Iraqis getting a minor victory of securing the Shatt Al-Arab fully for themselves. With the war at a close, the Gulf states would scale back the amount of their production as opposed to going full blast to help keep the Iraqis funded as in OTL. Thus, the 1980s glut would be avoided or at least seriously mitigated, further bringing about more support for Nuclear Fusion in the United States.