[nascarnation]

Given the demographic trends, I think you’re correct.

The only confounding factors I can see would be

1) markets finally puke on money creation making entitlements too expensive to continue at present levels

2) a 3rd party candidate (would have to be a liberal analog of Ross Perot, egotistical, famous and rich) lets us win with a plurality.
Bloomberg is one possibility, but he’s tight with the Clintons and would never oppose Hillary.

[Kip Russell]

I fully expect the United States to adopt some form of Euro-socialism in the next 50 years. We're already partway there...but by 2050 our top marginal tax rate will likely be in the 50-75 percent range.

Can we survive such an economic system? Sure...depending on your value of "survive". While Europe certainly sees its share of economic crises, it's not as if they've seen their economies utterly collapse in the last 50 years. However, things that occur regularly in such countries such as crippling public sector strikes and massive redistribution of income are, I'm afraid, not too far in America's future.