I will begin by recalling Mussolini's own definition of fascism: "the union of state and corporate power".
That is something to which everyone who values their own freedom and that of their children should object. But, RFK Jr.s' analysis of how that union of powers arose in the U.S. is wrong.
It's not that the corporations have hijacked the government, it's that the professional managerial class has hijacked both corporations and government. We no longer live under capitalism. The capitalists, whose claim on profits lies in their own resources being at risk in the enterprise, no longer control anything other than a handful of privately held corporations. James Burnham was prophetic, rather than descriptive, when he saw the rise of the managerial elite.
Professional managers at Blackrock, Vanguard, State Street and Berkshire Hathaway vote most of the controlling shares in American corporations, not the capitalists, the beneficial owners of the capital, who include a lot of us through pension funds and mutual funds. Professional managers in the intelligence services collude with professional managers in tech companies to censor news on behalf of their favored candidates for office. Professional managers drive the rise in university tuition and the leftward drift of academe (yes, outside of colleges of education and departments with names of the form [affirmative action beneficiary group] Studies, the administrators are the left-most part of university personnel, not the faculty), subvert civil rights groups like the ACLU and ADL to replace their original purposes with "wokeness". And there are rotating doors between the corporate world, government and the non-profit sector, so that professional managers from one will turn up in another, still looking after the class interests of professional managers. We no longer have capitalism, instead, we live under managerialism, which Burnham foresaw would lead to totalitarianism, as it will if it is not stopped somehow.