A good argument can be made that the GOP is the most destructive force in US history.

The Republican Party fairly gets credit its opposition to slavery and its limited support of the progressivism of Teddy Roosevelt. In almost every other crucial policy debate and in every critical period of our history, the party of the right has behaved atrociously.
It isn't only that whenever the choice was/is between what is good for the nation as a whole as opposed to the narrow self interest of the monied class, they unerringly line up with the plutocrats.
They have coupled their slavish devotion to great wealth with some of the most undemocratic, dishonest tactics imaginable.
It was not enough to oppose FDR on policy matters. He and his wife were vilified in the most crude possible ways.
It wasn't enough to take issue with Truman/Acheson/Marshall foreign policy. These patriots and innocent by-standers were called traitors and communists.
It wasn't enough to debate those who were opposed to the Vietnam War. Nixon and his party, burgled, audited and disparaged honest skeptics of a tragic, misguided conflict.
It wasn't enough to offer opposition to Bill Clinton's centrist efforts. The GOP impeached him on his reckless sexual behavior, while libeling Bill and Hillary as drug, dealing, murderous hillbillies.
And now we have a modern Republican Party that is so hateful about both Barack and Michelle Obama, that they have thwarted every attempt to pull this country out of the ditch that W and his Party drove us.
This is a record that ought to shame them into silence. The saddest aspect of the situation is that the Ryans, Cruzs and Bachmans perpetuate policies and tactics which are reprehensible.