Originally the idea of having a two-party system was to make sure there were adequate checks and balances to keep everything in place. Now people attempt to stack the deck with people in their own party thereby defeating the whole purpose of the double parties. And both sides are out for what they can get for themselves.
History have shown again and again that political parties have done so. Notice the current trend. Before and after the Civil War Republicans was hated in southern states and met with large amount of animosity while embraced in the areas such as New York, New Jersey, Pensylvania... pretty much entire northeastern region.
Now coming to the modern times. The staunched Republican state of the world is Texas (what an irony from the largest haters in Civil War against Republicans) are now standing defiant against Democracts.
Today's a lot of parties have gone way out of touch with reality and simply seem to do nothing more but argue and go nowhere. There seems to be no union on any topic and the worst of all a lot of problem solutions from both parties presented in the government floors are not supported by scientifical data, but by lawyers who use every and any tool possible to push their personal agenda in pretence of self righteous glory.
Some of the prime examples would be Frank Lautenberg's Lautenberg Amendment - highly unconstituational and in many ways cowardly passed act, hidden in the large book of the proposed laws on immigration called Omibus of Appropriations. Frank Lautenberg cared little about immigration, but wanted to create more control towards Second Amendment.
George W. Bush pushed for Operation Iraqi Freedom completely based on a lie coming from very unreliable source who pretty much told him what he wanted to hear.
We need an instant run-off system, where candidates are ranked, if there's no one over 50% the last place in the first round has his votes redistributed to who ever the voter ranked next and then in the second round and all future rounds it repeats itself until one candidate has over 50% of the votes. This would have the effect of encouraging the victories of more moderate candidates instead of polarized far left liberals and far right conservatives. It would also mean candidates would reflect the interests and needs of their constituencies more closely, and there would be less negative campaigning. In fact candidates would be saying "Rank Me #1 and Rank So-and-So #2" creating a culture of respect between political hopefuls. Instant run-off voting is America's hope for the future. We just need enough people pissed off enough and demanding it that the current politicians start joining in and voting for an instant run-off voting amendment in order to save their careers and there's enough of a push that those who don't are voted out of office.
The role of political parties is to throw rationality and compromise into the wind so that you can bring progress made by the government to a grinding halt just so that you can implement your own beliefs no matter what the rest of the country wants to do.... And political parties still do that very well, so they most certainly have not lost their purpose
Political parties are supposed to promote a certain representative of the people who represents their values and beliefs. The Electoral College is still used, and it forces a nominee from each party, so it emphasizes political parties every time that four years are up and it is time for another presidential election.
Political parties have always been an important part of American government. Without the two-party system, we have a better chance of falling into Communism. We need the checks and balances that the parties bring to each other to keep one party from gaining total control of the government. If one party did gain total control, Communism could be the result.
Having political parties allow us to limit the number of people being voted for, and helps fund them. With out them, you'd how too many people up there, and you wouldn't know anything about them because they couldn't afford to advertise themselves as well. There is a reason for the party system... If you have 3 candidates, your likely end up with someone being elected with only 35% of the national vote, which isn't the majority. A 2-party system allows for 2 people, so no matter who is elected, it's the majority who wanted him over everyone else.