I hesitate to state the differences between the current parties.
I would have had no problem before Trump. But now, the ideas of former leaders of the Republican Party are not acceptable: the ideas of Reagan, Bush, Bush, Bush, Dole, McCain, Romney, Kasick are all too far to the left for the current party. The obvious example is that before Trump, the Republican Party stood for smaller government and lower federal deficits and debt. Now government spending is fine as long the expenditures helps Trump and his allies. A trillion tax cut would have been impossible before Trump.
Also, it is difficult to make believe that the current Republican Party believes in consistent policies, other than whatever Trump states that he wants today. I'm not criticizing; he has the support of 94% of his party. Almost by definition, a transactional politician cannot be pinned down with regard to doctrine.
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Until Trump, certainly before 911, the US had a consistent foreign policy, and a domestic party based on compromise. IMO, this worked very well between 1980 and 2000; that is, from Reagan through Bush, Clinton, and Bush Jr. I could also say that I believed the system worked well from 1960 onward, but there were lots of crises in the 60's and 70's, ones that we are still recovering from (especially in the Middle East).
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We might consider that we once spoke of declining deficits and retiring the debt. Under Eisenhower and Clinton, we even had a couple of years of budget surpluses.