Does the future of america rest in the hands of the democratic party?

each year america becomes a little more liberal, this is clearly shown this election by how obama (a left wing candidate that few had heard of 4 years ago, entered politics in 1997, and serverd in a state government until 2004, as well as is a minority) is clobbering john mccain who is a straight laced white guy who is a war hero and has been a senator since 1987, now the percentage of this country that is black or hispanic has been steadily going up for the past few decades and shows no sign of stopping (i do not mean that in a racist way, that is a fact that you can look up) now 88% of blacks vote democrat as well as strong majority of hispanics that have a fast growing population because many of them are catholic and dont believe in birth control, now this means that as our nation continues to get more and more democratic that one day that the democrats will continuously win the whitehuse and control the vast majority of congress, do you think a 3rd party will emerge, or what