One of our other threads claimed that growth is all due to light industry and that heavy industry was actually declining while the light industry more than picked up the slack.
There seems to be some merit in this- steel production has been fairly flat:
Automotive production seems to be on a long-term downwards trend:
TxCoatl1970 and TheMann are more or less correct in their approach- US companies became complacent, unwilling to innovate, and perfectly content to remain in a domestic market. Looking at several sectors, you find a failure to invest in technological improvement until for many firms it simply was too late, the cost of catching up too high.
Autarky is of course complete nonsense, and it is the complete opposite of what the US ought to be doing- the US needs to be focusing on finding export markets for its goods. In order to do this you need trade agreements with other nations, and ideally if developing nations can discard protectionist policies sooner, this would push development (and thus markets) somewhat sooner.
For example with the steel industry, foreign firms adopted the more efficient continuous casting method, but US firms did not. Had trade barriers been lowered, this increased competition might have become apparent sooner, stimulating the adoption of such technologies, rather than later when the costs of catching up were too high to surmount.
Of course, for steel, you need markets. The US shipping industry all but collapsed in the face of foreign competition. The Jones Act, which prevents any foreign flagged or foreign built ship from shipping goods between US ports, played a key role in its demise. This meant that any American shipping line could only buy American-built ships, a large protectionist barrier. As there was no incentive to increase efficiency or productivity, American ships became more and more expensive, until their captive market, US shipping lines, were driven into bankruptcy! If US shipping lines have the option of buying foreign-built vessels, not only will they be able to stay afloat for that reason, the shipbuilders will be compelled into becoming more competitive. And the steelmakers will have a larger market.
We see the same thing in the US Navy- it's closed to foreign competition and thus the Navy is completely subject to the mercy of the shipbuilders. (Oddly, the same people supporting such protection are quite often the same people saying we should cut defense spending...)
And it is correct to note the parasitical, role played by the rise of "shareholder value" short-termism, butterflying that (and corporate raiding) would definitely give companies more room to make improvements with the view of long-term sustainability and profitability rather than short term returns. (Whether this is true, of course, is the current debate in economics today- as is evidenced by this year's Nobel Prize given to economists for their work on the theory of efficient markets- who hold opposite opinions!) You see that the shutdown of Bell Labs is attributed to the focus on "immediately marketable" fields.
There would need to be a system of educating factory workers about the new technologies... or perhaps increasing foreign immigration.
Looking at our present (semi)revival, we see that one of the major things propelling it are low energy costs in the United States- here shale oil and gas. Lowering energy costs would be a major help in the 1970s- ideally/most plausibly from nuclear energy. We also see low freight rail costs playing a role.
Looking further in the past, industry would also be helped by a stronger rail sector, which was killed largely by government intervention and favouritism (for airports and the government-built IHS). If the ICC can approve mergers sooner than they did, this would help. If, for consistency's sake, the government agreed to create an Amtrak-analogue sooner than it did in reality, taking over the loss-sustaining passenger sectors, this would help avoid the total collapse of the rail industry and help freight. Deregulation (heavy and restrictive cost controls) and a successful weakening of labour (in all sectors, not just rail) would help as well.
A lot could be done, but it involves more liberalism, not less.