Would advocates of an elitist democracy support the consequences of the Citizens United v. FEC decision?

The term "elitist democracy" is almost an oxymoron here because democracy, by its very nature, advocates an even playing field for everyone rather than elitism. One might wish to think about the more technical "meritocracy," which assumes that within a fully democratic environment in which everyone starts at the same place, people have different levels of skill and ability. Thus, some will do better than others at the end, just as runners who begin at the same starting line finish in different places.
The key point of Citizens United was that it allowed corporations to spend money directly in unlimited quantities to campaign for political candidates. On one hand, this fits with democratic principles in that it allows everyone unlimited free speech in the political arena. It also fits with the concept of a meritocracy—that those who by their own efforts have attained great wealth should be allowed to spend their wealth as they see fit in advocating for ideas or candidates they support.
On the other hand, many advocates of meritocratic democracy would argue that this decision is essentially antidemocratic, as it places a tremendous amount of power in the hands of a small group of the very wealthy and powerful. It allows large corporations, often with ownership through anonymized shell companies, to influence politics by buying large amounts of advertising and spreading "fake" news favorable to their interests. It can lead to rent-seeking, in which corporations profit from tax breaks and subsidies in return for throwing money at political campaigns. It may allow, for example, natural resource companies to buy out public lands for private profit at fire-sale prices. In this way, it can lead to behavior that is fundamentally undemocratic, with large corporations and rich individuals buying their way to ever-increasing wealth and power; people will not have equal influence on the political process.