both are centrist parties but the republicans have moved way to the right in recent years thanks to super PAC's and the influence of the Koch brothers, Adelson and other billionaires helping to elect people who will fight for their interests .. you can't say both parties are the same anymore. no such thing as a liberal republican anymore, they've been wiped away. but there are still conservative democrats, just look at a state like Arkansas which still has a democratic state senate and legislature. same with Kentucky and WV too. those are very very very very conservative states but the state governors are democrats and were elected in landslides.
Correct and also kudos to your other post above regarding the fallacy of only talking about tax rates. Just one piece of the puzzle.