Planting a flag on the moon.
Electing a black man president.

he was certain it could not be done until he saw it done.

I am guessing you are referring to Sen. Sanders policy and the attack that they are impossible... the difference is the American Revolution was more of a "new"thing, revolting against the monarchy at that time was a rare thing and on top of that the form of government chosen made it very rare outside of Switzerland and Netherlands. So that was understandably impossible. Sen. Sanders policies are absolutely not impossible and are enjoyed in many Western and Northern European countries. The attack of that they would not work because those countries are smaller, are destroyed when population is compared with the size of the economy. The attack that hose countries are homogeneous in identity I really do not understand, because don't all people no matter their identity think their Healthcare and Uni tuition is a right and need for a prosperous future.

The only attack that I believe can make Sen. Sanders policies impossible is that America is not ideologically behind his proposals, if that is true I can live with that. Ideology is just a matter of thinking and usually correlates with the status quo acceptance or rejection, it can be changed.

In the case of American ideology in my OPINION it needs to be changed and from anecdotal evidence of my life experiences living in a lot of those countries they are begging us to change it.

Americans support them. Even the "crazy" ones. For example, single-payer gets 60-70% support depending on the poll. Redistribution of wealth gets >50% support (number varies significantly by poll, but still a majority).

These results have been consistent for a long time (to be fair, redistribution has not been polled until recently).

The ideology is there. The politicians are blocking it. That's why our party works so damn hard to make sure the "wrong" kind of Democrat does not win.

I have an annoying habit of only looking at the US elections (esp post-citizens united) as being decided by a moneyed aristocracy. Yeah, I agree most voter's do already agree with Sen. Sanders policy, but with weird primary rules, party affiliation, low voter turnout and barriers at every corner, it does not seem to much matter in the US... sad

but you are definitely right thank you