For decades the six national committees of the Democratic and Republican Parties dominated the American electoral landscape.That's simply not correct. It's not even close.
The first cut at this would be that the formal party committees haven't really been all that important in the overall electoral landscape. Candidate campaign committees do the bulk of campaign spending -- and they raise most of their money from individuals and PACs (and, in the case of presidential candidates until recently, from public funds). The party committees did some direct spending and made some contributions to candidates, and have also been important in various other ways such as candidate recruitment and training, but "dominated"? No chance -- not even in the age of soft money in the 1990s, when formal party organizations could directly raise and spend quite a bit. I note, by the way, that Politico went to former chairs of the various committees to confirm how important they were; I suspect they would have heard a very different story from people whose experience was in other portions of the campaign world.
That's just the beginning of it, however. The mistake (in my view) that the standard political science literature makes is to treat those six national committees as "the party" when analyzing the importance of various money sources. As I've said, there's a lot of party money in elections, but only some of it is raised and spent or donated by formal party organizations (such as the DNC and RNC). Plenty of individual donations raised by candidates should properly be thought of as party money, if it's from individuals who habitually give to multiple, same-party candidates, especially if it's raised by party-loyal bundlers. PACs have traditionally been thought of as raising interest group money, but many PACs are party-aligned or from party-aligned groups -- including (Congress-based) leadership PACs. I'd like to add it all up, but we can't; we don't really know yet what percentage of all money raised should properly be thought of as party money, what percentage is interest group money, and what portion is from true unaffiliated individuals.
So what does the introduction of Super PACs do? It's hard to say. As far as parties are concerned, there are basically two issues: what portion of Super PAC money will be properly thought of as party money (and how does that change the overall percentage of party money in the system)? And, how will the emergence of party-loyal Super PACs change things within the parties?
As for the second question, it's quite possible the answer will be: not at all. If Super PACs basically mean that people who previously were important bundlers within the parties are now doing more or less the same thing, but with a different organizational structure, then perhaps it's not very important at all. On the other hand, the new structure certainly could change things. If those bundlers will now be not only raising but also directly spending money, it could empower them within the parties, perhaps at the expense of those with other types of expertise. It might make party co-ordination -- always difficult in a very decentralized system and even more difficult because of the effects of campaign finance laws -- easier if it breaks down some of the legal restrictions against co-ordination, or harder if it proliferates the number of quasi-party organizations.
I would say that in the short run, rules disruptions tend to be bad for parties, at least American parties, because co-ordination problems are so inherently difficult. Stable rules allow everyone to work well together. New rules may wind up temporarily empowering whoever is the first to figure out the loopholes and nooks and crannies, and while that might be party operatives it also might be someone with personal or interest-group goals.
At any rate, the idea that American political parties are normally hierarchical organizations with the Washington committees at the top is wrong now and has always been wrong. Formal party organizations are important, but they're generally role players, not top dogs. As for reporters, the big questions to ask about the new Super PACs, at least the ones that appear to be "shadow" parties, is who is making the decisions and how: are these new organizations coordinated with and perhaps constrained by other party actors, or are they free to do whatever their organizers want? Do they function as factions within a party? Are they following the lead of other party actors, either in formal organizations or informal networks, or are they themselves important signalers of party preference? That's the sort of thing we need to know if we're trying to understand how something fits into and potentially alters the party structure.