Those demographics bode poorly for the GOP too.
People 18-29 went democratic by 10 point margins in 2004, 22 points in 2006 and 34 points in 2008. Right now our generation makes up about 25% of the electorate, we will make up 33% by 2015 or so.
Single people (both men and women), and especially single people who have kids lean democratic far more than married folks. Singles are growing dramatically as a % of the country.
http://www.motherjones.com/mojo/2007/11/unmarried-women-are-democratic-partys-christian-evangelicalshttp://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/11/27/MNVTTDNOM.DTL&tsp=1Religion is also changing, we are becoming a more secular, non-christian society. The % who claim to be christian has shrunk while the number of non-believers doubled in the last couple of decades.
The GOP has not only lost professionals, urban dwellers and non-whites, they have also lost young people, single people and non-christians. Obviously demographics are not destiny, but if you are in a demographic that the GOP is openly disdainful for or that they do not share your values, you likely won't vote for them.
Also, once we get meaningful progressive reform, the union movement will restart. Having a strong union movement will further promote progressive action since unions increase voter turnout and funding for progressive candidates.