You say “The most important problem facing Republicans is that they have convinced both themselves and their voters that the Democratic Party represents communism and moral depravity, and that therefore anything and anyone associated with the Democratic Party must be shunned and avoided.” You seem to misunderstand the results of recent elections: the Republicans have a majority in Congress, and in the Senate and they have a sort of republican President. The truth is the exact opposite:

The most important problem facing the Democratic Party is that they have convinced both themselves and their voters that Republicans represent Fascism and moral depravity, and that therefore anything and anyone associated with the Republican Party must be shunned and avoided.

The Democratic Party risks being completely irrelevant if they don’t move towards the centre and act to block the Tea-party extreme right of the Republican Party. If a few Democrats had voted for the health care reform bill, they would have become relevant again, would have disempowered the Tea Party and made them less relevant, and the Democrats could then say the Republican Party owns the mess which Trumpcare is almost certain to be, and stop taking the blame for the defects of Obamacare. They missed that opportunity because they are as fanatically partisan as you would like to portray the Republicans as being.