The two-party system the US has currently come by is, to be terrifically honest, the greatest factor in isolating people from power in the US.
The formation of political parties are inevitable - that much is true. One doesn't necessarily need to say they exist to make implied political organization explicit. If they also end up uniting the executive branch and legislative branch, so be it - that, too, is unavoidable. The whole scheme does reach the point of absurdity, though, when parties become synonymous with political leaning - not the more nuanced actual platform identity each party has, but simply the "left" and "right" in general. The two large categories here serve to make determining political leaning trivial because this doesn't reflect a person's reasoning on isolated political issues, but instead cuts down to the serious philosophical question of what seperates left-leaning thinkers from right-leaning ideologues. What can be safely said, though, is that this does not change often in a person.
Politics then becomes annoyingly predictable - by way of easily determining the political leanings of the judicial branch, seperation of powers is made entirely worthless. All this interleaving of elections merely serve to increase the frequency at which this question is asked - the more hostility, the more resulting self-reassurance in response, and, as a result, less nuance and less change.
Polarized politics elevates this from the level of niggling curiosity to farce, though - heavily contentious bills like ACA or budgetary appropriations for the next two years, for example, bypass the legislative branch entirely and simply present the two-party system in all its ugliness: party leaders simply hashing out a deal in the White House, regardless of which party happens to hold the executive branch. The difference, then, being the complete lack of transparency - again, politicking itself taken to the logical extreme. Seeing the House and Senate reduced to a rubber-stamp piece of political machinery is merely the sideshow. While I generally frown on divining what the Founding Fathers would like to think, subverting the system in this manner would most likely gain disapproval. For obvious reasons.
I do disagree with the fundamental argument that both parties are the same, and merely two sides of the same corporatist coin: this may sound woefully naive, but channel some of that 2008 bliss. The average legislative branch Democrat may or may not default to lobby-pleasing mode as an invariant independent on party orientation, but they are politicians nonetheless; given good leadership progressive policy will fit like a glove into Democrat rhetoric or at the very least in direct opposition with Republican talking points. The fact that unions do represent a sizeable chunk of Democratic support does help - if they can be convinced a welfare state bolsters the cause of unions by way of reducing the load on businesses.
Given convincing electoral reform (first-past-the-post rears its head here as the scourge afflicting the level of political dialogue), though, the two-party system in the US has a chance of slowly being eroded from the outside. This is because members that deviate from the party line exist in both parties, and this is not simply a case of toeing the radical-left or radical-right line - single-issue parties seem like a tremendously good fit to the here-today gone-tomorrow nature of political zeitgeist in the US, and a revitalized electorate may finally push past the apathy of the newly minted voter and lead to the formation of variations-on-a-theme parties. The former is unfortunate; the latter is guaranteed, and in addition, ultimately does create endless but convincing competition in the US.