Yes, I agree.
I think that USA will evoluate to the left after Obama's presidency. Obama is a great politician, as great as Reagan. Reagan managed to destroy New Deal's Social-Democrat/Liberal coalition and build an ideological system based on the hate of federal government and a return to traditional values. Today, these ideology is strongly discredited by Irak war and economic crisis. Obama's words and acts are particularly audacious, and they could deeply change Americans mentalities.
In 2050, social issues will be totally inexistent, because they are old-fashionned. Abortion, homosexual civil unions... are necessary progresses. Economic issues will probably be preminent in the political debate. I think that Democrats are going to seem more to european social-democrat parties, promoting welfare state and reduction of inequalities, whereas Republicans will continue to advocate economical conservativism.