This is frequently misunderstood, for decades on the left, but now on the right as well, and even the libertarians, who should know better, dammit. Start from this interesting though not radical article in City Journal. The rich do have outsized influence within the narrow domain of their own industries in which they are rent-seeking and trying to get government protection. Hence the shift over my lifetime of large businesses, including banks, from supporting Republicans to overwhelmingly being Democrat contributors at this point. The tipping point was actually decades ago in the Tip O'Neill era, despite rhetoric to the contrary.
But because they seldom focus their energies outside of their own narrow interests, they don't affect the larger culture anywhere near as much as is widely believed. A few decide to devote their fortunes to more general causes. They do have common interest in tax and inheritance legislation and general policy and can rally around this. But mostly not. Numbers showing how much "wealth" the 1% have regularly overlook the transitory nature of the Fortune 500, the lack of liquidity this group has, and the actual beneficiaries of they contributions. The Koch brothers were reviled for their libertarian (which means occasionally liberal but always counted as troglodyte conservative) causes, but at the height of their cash sendout, they were #6 overall, even when counted together. They were outliers among the liberal contributors, which is why they were hated. When any group has dominance, they very quickly want absolute control. (Sidebar: This is how you get HUAC and McCarthyism, which represented views which were majority but not fully dominant. They then tried to make themselves fully in control, which was of course ridiculous. The 1950's were not an age of conformity, but of ferment. The Adlai supporters loved painting themselves as an oppressed minority, but they were just slightly out-of-power. See the elections of 1958, which established decades of Democratic dominance in the house and Senate. It has been a common pattern to claim victimhood just as you are on the verge of assuming power and to wrap yourself in that flag forever. The name Clinton might occur to you.)
Power remains distributed in America, and in all market societies. Only by moving toward rent-seeking, crony capitalism, corruption, and socialism do we get to concentrated power. And of course, we have plenty of that in America as well. The free market is not the cause of that, but the only reliable protection against it. Oh, and the internal morality of the powerful, which in Western societies has at least some value, or outgroups would never have any rights whatsoever and much of the Third World would still be colonies instead of independent. Even in the West you can't count on that, but it's something.