... Some have argued that the USA was at least potentially the stronger power.
Not much argument about the 'potential'. The industrial capacity of the US 1935-1955 is clear. The real argument is over how much could have been realized and then used outside the western hemisphere.
1. Lack of planning for global war. The US Color Plans were largely outlines & had little depth. The primary exception was WP ORANGE which the US Navy had studied extensively for near three decades and developed detailed sub plans for how the war would be prepared for and executed. The flaw was on the US Army side, where the planning was still largely theoretical, and assumptions were largely untested by rigorous exercises. The fault largely lay with Congress which funded the Army at cadre levels and rejected repeated requests for a adequate war planning staff. The examples of Britain, France, Italy, Germany, and even small nations like Belgium showed that realistic planning for military mobilization and the supporting industrial mobilization required a robust research staff, including economists, business managers, industrial engineers, and a regiment of clerks. The US Navy by necessity had that, as a fleet could not be built or maintained without a staff who could plan long term industrial projects. The problems encountered by the War Department/Army during the 1915-1918 preparation and mobilization apparently taught Congress nothing about funding adequate planning.
2. The tiny professional cadre of only 17,000 - 20,000 regular army officers was wholly inadequate for rapid mobilization and training of a army of the size needed for battle in Europe. The 30,000+ National Guard and 60,000 to 70,000 Army Reserve officers lacked depth in their training. It was expected 10-12 months finishing training would be required to bring them all to combat readiness. To put it another way the mobilization plans anticipated only nine regular Army divisions & three corps HQ ready for overseas service in six months, and 10-12 RA, 30 NG, & a few more new Reserve or AUS divisions ready inside one year. Another 20 - 25 Reserve/AUS divisions might be ready at the 18 month mark. So, if the War Powers Acts mobilization of October 1940 had continued past the summer of 1941 the US might have had 60 ground combat divisions of various types read in early 1942. That assumes a full war time priority for this mobilization & not at the peacetime pace of the 1940-41 mobilization.
3. Could the problem of poor planning for industrial mobilization been overcome. (back to 1) The partial mobilization of 1940-41 showed severe problems in attempting to rearm rapidly under peacetime conditions. How much more efficiently that could have been under war time law is difficult to gauge. The US Army Chief of staff had a plan ready to reform the War Dept procurement and distribution system. If that could have unclogged the system we will never know.
4. The problem of deploying a large air force is even more difficult. Germany managed to reach aircraft production levels of near 80,000 aircraft in its peak years and keep over 6,000 of them operational on any single day in its peak years. The Devils Alliance of Britain and the USSR managed to reach near 70,000 aircraft between them for much of the war. That they had a large portion of multi engine models while the German production was dominated by single engine models must be noted here. The Alliance engine production was near triple that of Germany. Conversely US aircraft production never exceeded 25,000 flyable aircraft, predominately heavier models. There are reasonable arguments the Ford, Boeing, Douglas, Martin, & other new manufacturing plants could have been built on quadruple scale, or even larger. Those projections lead to a possible US aircraft manufacturing capacity of 100,000+ aircraft a year, and engine production rivaling all other nations combined. I'll leave those arguments for others to judge.
There are a large number of details in all this. That the US Navy was funded in carrying through the 'Two Ocean Navy Act' through 1944 & its successful execution of that expansion, suggests what might have been accomplished given adequate time & funds for preparation and planning.