Actually, this was a duplication of the Democratic strategy of the 1840s, which was to forge an alliance between Southern planters, Western farmers, and predominantly Irish immiggrants up north around a program of states' rights and hostility to the ex-Federalist financial elite.
And concerning Justin's citation of Shakespeare's Othello as evidence that racism goes back to at least 1600:
The example is misleading. The curious thing about Othello is that while we get a lot of info about the hero's color, we get nothing about his race as the concept would be understood according to modern American racial ideology. I.e. there is nothing about the kinkiness of his hair, the thickness of his lips, etc., etc., all of which are more significant in the contemporary U.S. actual skin shade. After all, David Dinkins and former Manhattan Dem Chairman Denny Farrell were both quite light skinned, more so, for ex., than many Indian immigrants. Yet they were (are) "black" whereas the latter are not.
Dan Lazare