Why should I vote Democratic party?

I'm a non party registered voter. 90% of the time I vote Republican. I'm in the middle cl, continued to see an increase in income these last 7 years, no health care issues, carbon footprint of 1, no kids, own my own home and take vacations when I want. So far all I've seen is that Democratics want to increase my taxes and NONE of the programs they are suggesting seem to help me in the least. So exactly why would I vote for whom ever the Democrtic canidate turns out to be?