Sorry, Founding Fathers. You had some good ideas, but they're not that viable anymore.
The United States, and maybe some other countries, form their governments based on winner-take-all voting and a strict separation of powers between the legislative and the executive branches.
But that system doesn't work well anymore. In the United States, it's led to gridlock, but not good gridlock. There are times that a government needs to be able to act; whatever your political beliefs, you have to agree on that. The entire US system is set up to slow down government, and political parties make that even worse by deliberately gumming up the works when they don't like where things are going.
The US system leads to a second vice that's prevalent among (but by no means peculiar to) Americans: black-and-white thinking, the idea that there are only two sides to every issue and that you're either all on the right side or all on the wrong side. Taxes must be higher/taxes must be lower. Health care must be reformed/health care is okay. We need to increase troops/we need to bring troops back: Americans, especially, refuse to see gray areas, and that in part is because the two-party system that Americans have let their politicians create enforces that dichotomy.
Over time, gerrymandering and the government's control over access to big-time politics (including the horribly wrong McCain-Feingold legislation) has entrenched Republicans and Democrats as the parties in power, and has created districts that are "safe," meaning that are solidly Democratic or solidly Republican. Karl Rove furthered the politics of entrenchment by showing how appeals to the "base" could win elections without having to bow to moderates. This all has led to parties pandering to the far-out wings of their constituents, in most cases -- or, in the opposite, pandering to the far-out wings of the other parties, as Presidnet Obama has been doing with his pointless "bipartisan" efforts at passing health care.
A parliamentary system, with proportional representation, will help end many of those evils. Proportional representation -- awarding seats in the legislative branch based on percentage of vote rather than on winner-take-all voting -- will encourage the growth of political parties and viewpoints that do not rigidly adhere to a party line or black-and-white thinking, by letting members of Congress (and thus the executive branch, which is drawn from the legislative) be elected across a broader range of political thought. It will be possible for a Republican to be pro-choice, for example, without ending his or her possibility of getting elected, or for a Democrat to be hawkish.
Parliamentary representation makes the presidency -- or head of government -- more a part of the law-making branch, encouraging faster response time (when necessary) and more direct involvement. Right now, we've got a government in the US in which the president is the only nationally-elected figure, and he makes nationally-broadcast and nationally-voted-for promises... which he then is absolutely powerless to put into action, unless he can first get Congress to sponsor some sort of legislation to do that. So President Obama promises universal health care by the end of his first term...
... he really did, too:
'We can have universal health care by the end of the next president's first term, by the end of my first term,'' Obama said, bringing 600 union workers to their feet during a question-and-answer session with members of AFL-CIO affiliated unions...
... so don't forget that...
but then he has to wait for Congress to dink around and pass some stupid watered-down bill that he hopes will be the first step or something. If the president was part of the legislature, he could make that promise, then put the bill into the first session and shepherd it along -- providing not just a response to his promise, but accountability.
44. Stop teaching any math past algebra and geometry to almost everybody, and instead just provide a general theory of math to high schoolers.
30/31. Impose a luxury tax that increases exponentially the more people spend/Never watch another Brad Pitt or Angelina Jolie movie again.
26. Require everything we build, from here on out, to get at least some of its power from the sun or the wind.
13. Ban driving any kind of automobile, motorcycle or other personal vehicle within 1-2 miles of downtown in any city with a population of more than 100,000.
12. Abolish gym class; instead, teach kids to play musical instruments.
11. Change copyright laws to allow anyone to use anyone else's creative work provided that the copier pay 60% of the profit to the originator and that the copier not cast the original work in a negative light.
10. Have more sidewalk cafes and outdoor seating.
9. When you have to give someone a gift, ask them what they want, and then get that thing for them.
8. Never interrupt or finish someone's jokes.
7. Periodically, give up something you like for at least a month.
6. Switch to "E-money."
5. Have each person assigned one phone number, and then add an extension for the various phones and faxes that person might be reached at.
4. Abolish Mondays and Tuesdays.
3. Don't listen to interviews with athletes or comedians.
2. Have "personal cashiers" at the grocery store.
1. Don't earn more than $200,000 per year.