As a Canadian who moved to the US a couple of years ago...Apple, meet orange.
Immigrants in Canada didn't jump the border, or were the siblings of people who jumped the border. The Chinese you see in Vacouver were investors from Hongkong, not the kids of Tawainese who hid pregnancy so their offsprings could get citizenship to save on money when they get sent to Harvard.
While there's bad apples everywhere, in the US has a SIGNIFICANTLY higher percentage of people who are only there to leech the system. And the people on top of the system are also a lot more likely to want to leech off of the people. You thought Harper was bad, he got nothing on the politicians south of the border.
When you look at the state of the $$$ used for these policies in Quebec...they're very close to going poof. These systems depend on people using them in a way that benefits society. A high percentage should be professionals who paid taxes, who will use this to be in better shape to go back in the work force and pay more taxes, and for the benefit of their kids, who will be raised better, and someday pay more taxes, so the system can keep going, and compensate for the percentage of people who won't be giving back (often because they can't, for various reasons, some good, some bad. It averages out).
Do the same thing in the US, and you'll have such a high percentages of people coming just to leech it (they don't even have an effective way to filter out people who shouldn't be eligible...actually, they have a HUGE percentage of the people who actively will fight against any such policies...so anyone who manages to get in the country can tap into all these resources) and never give back, that it's always a net negative.
Thats why socialized healthcare can't work the same way it does in those other countries. That's why this wouldn't work (it BARELY works in the other countries where its implemented...a slight shove in the bad direction and they would not be able to afford it).