Actually, the Republicans don't do that, they currently "just say no" and their purpose is to block anything and everything presented by the administration.

I imagine there are political parties like that in Australia from time to time as well.

I understand the Washington Post has an article linking the Australian election with the American political scene. There are many similarities. While Liberal Party is not as conservative as the Republicans it does oppose almost everything the Labor government did. This despite, unlike the rest of the world, we had no recession. However we do have debt . The Liberals are saying they would cut all Labor spending to reduce debt.

Gillard has tried to neutralise this by saying we will be in surplus in three years. Her policies are similar to Rudd, she has only been in power three weeks. However she tries to say she is more conservative on stopping a mining tax and being tougher on immigration. However the Oppositions says it will be even tougher.

There is a preference voting system here which means you must given a second preference. Most people follow How to Vote cards issue by the parties. This means most Labor voters will give their second preference to the Greens. This might give them the balance of power in the Senate a position which will make it hard for either major party to get its legislation through the Senate. While it is more fairer to have preferences but it does cause problems.

Vested interests in Australia are similar to other countries. Big companies like miners, newspapers, oil and coal suppliers, but balance by unions and environmental groups. The Churches are less powerful here, the Prime Minister is an atheist living with a boy friend. Both leaders were born overseas although the Opposition leader is a Conservative Catholic.

The Australian election has resulted in no clear majority for either major party. We will have a hung parliament where one of the major parties will have to govern with the support of independents and greens. This is similar to the UK result with a minority government. It also might involve a conservative Party governing with the support of left wingers like the Greens. Or it might result in Labor continue to govern even though it lost so many seats. The Greens will have eight seats in the Senate and will have the Balance of power.
This is similar to the position in most of Europe where there are no longer two major parties> I am not sure the same position will apply in the USA. But if the Tea baggers form a separate party it could The result is a warning to Obama. He could lose a first term election.

I think if teh Tea Party form a political party with candidates, more harm will be done to the Republicans. The Tea Party could very well split the conservative vote, and hand the election to the Democrats.

As for the Hung Parliament thing, that is a look at the future as far as we are concerned. The Lib Dems insisted on a referendum on adopting the Alternative Vote system, and if the result is a yes vote, we will see many more Hung Parliaments.

Jackdiddley. Australia already has a preferential voting system in the lower House which I think the Liberal Democrats want to copy in your country.
Our senate is voted on a proportional representative model so will always produce seats own by minorities. I doubt if the USA would agree to this but it is common in Europe. Unfortunately situations like this hung parliament will lead to more electoral reform along this lines.