I disagree. What the US has ended up with is two almost identical parties trying desperately to pretend that they are different. This fact has been recognized for decades by political analysts; in fact the earliest book describing the phenomenon that I have read was written about 1950 (sorry I can no longer remember the title or the author), but there are a number of other books detailing the lack of choice available to voters in the US.
As I mentioned before this has forced those on the US political left to choose one or the other of the two parties if they want to have any chance of getting elected. Unfortunately, these few true liberals are submerged by the much more numerous conservatives. As a result, it really does not matter what party is in power as the programs instituted are pretty much the same. In addition, most members of Congress have been hijacked by massive political contributions from big business. This pretty much insures that most US politicians will continue to vote the way their monied masters want them to.
Don't get me wrong. I am not saying that there are no liberals in the US. What I am saying is that liberal voters in the US have a very limited choice in the Republicans and Democrats.
Canada does have a real difference. For the past 80 years New Democratic (or CCF if you prefer) policies have been markedly different from Conservative policies and have strongly influenced the party platforms of the Liberals and Conservatives, forcing them to institute programs they would probably have ignored (universal health care being a prime example).
This is also true for nations like France, Britain, and other Western democracies. Left wing parties in these nations act like left wing parties. As a an example can you imagine either the Republicans or Democrats proposing a 75% tax level on the wealthy as has been proposed in France or the multiplicity of social programs in nations like Sweden and Germany?
The reality is, that if a political entity talks like a conservative, walks like a conservative, and implements conservative economic and social policies; then it probably is a conservative. That unfortunately, seems to be the case with both the Republicans and Democrats in the US. What Americans are saddled with is a party that is truly conservative and a competing party that is moderately conservative with a sprinkling of liberals thrown in for colour.
And BTW going massively into debt is not a liberal policy. The largest amount of debt added to the US National Debt has been the result of conservative policies. The Swedish Social Democratic Party (the world poster boys or girls for left wing policies) have always attempted to work from a balanced budget. The history in the US is that under Republican (conservative) presidents the US goes farther into debt.
Let's look at both the US Democrats and the Canadian New Democrats.
US Democrats want higher taxes on the rich, Canadian New Democrats want higher taxes on the rich.
US Democrats want higher government spending, Canadian New Democrats want higher government spending.
US Democrats want socialized medicine, Canadian New Democrats want socialized medicine.
US Democrats want gay marriage, Canadian New Democrats want gay marriage.
US Democrats want more environmental protection, Canadian New Democrats want more environmental protection.
US Democrats want gun control, Canadian New Democrats want gun control.
US Democrats want affirmative action, Canadian New Democrats want affirmative action.
US Democrats want access to abortion, Canadian New Democrats want access to abortion.
US Democrats want to end poverty, Canadian New Democrats want to end poverty.
US Democrats want more regulation, Canadian New Democrats want more regulation.
And so on.
Sure, there are differences, but there are a lot of similarities.
Of course, Democrats don't always get what they want. America is a right-leaning nation. Polls have continuously shown that the American populace is split roughly 40/40/20 conservatives/independents/liberals. It is also a country borne in the belief that the individual is paramount and sovereign, unlike Canada. But in states which are dominated by Democrats, i.e. California, they are far more liberal than the rest of the country, and are more left-wing than some Canadian provinces.
Also, one must be cognizant of political structures. Canada is essentially a democratic dictatorship. We have elections once every four years or so, and all the power is concentrated at the top. In America, power is far more diffuse, with legislatures having a plethora of rules, laws and constitutional bounds designed to create checks and balances, which can make it difficult for any one party to implement their agenda from the top down unless they have an overwhelming majority, not to mention the power of constituencies and lobbies that can make it difficult to implement their agendas.
Canadians tend to look at politics through the prism of healthcare, since it is intertwined in Canadian nationalism. (Never mind that every single other developed nation has some form of government health insurance, and that nearly half of all healthcare spending in America is funded by the government, but no matter.) But America has a vast and expansive welfare state, and governments at all levels have no problem implementing left-wing policies, especially in local politics. The city of LA, for example, has passed a law banning all plastic bags. In my liberal Democrat Florida city, I can't remove the beaver in the pond out back, even though the rodent causes my yard to flood since the leftists think it has as much right as I do to live there. FFS, where I grew up in Canada, we'd either call the city to remove it or get rid of it ourselves. So again, if one thinks that both the Democrats and Republicans are similar, right-wing parties, one is way, way out on the far left of the political extreme.