Racism exists everywhere, including some people in the Republican party. It's not the norm anywhere, or at least not morally acceptable or socially acceptable.
But if you want to argue that Democrats are all racists and anti-Semites but no Republicans are racists or anti-Semites -- it's a free country.
But if I were you, I wouldn't be surprised if that argument doesn't get very far.
I'm not arguing that "Democrats are all racists and antisemites." Nor am I arguing that racism and antisemitism are non-existent within the Republican Party. But I think it's fair to say that (1) on balance, the large majority of clearly racist and antisemitic public remarks made by public officials in, say, the last two decades, have been uttered or written by Democrats and (2) polling shows that Republicans as a group favor a US foreign policy protecting Israel's right to exist and flourish in significantly larger percentages than Democrats. (And yes, anti-Israeli views on the Middle East are a good proxy for antisemitic views in general.)
First, the amount of racism among members of the republican party is not relevant. We do not have to be lilly white in order to assess democratic racism. Racism in the democratic party is not excused by the existence of any racism anywhere else.
Also, we can accuse the democratic *party* of being racist, and institutionalizing racist practices without accusing *all* democrat *voters* of each being racist.
I would argue that is the case. It is unwritten (and written) policy to use race to further party goals. It is party policy to forment racial disharmoney. It is party policy to treat black Americans as second rate citizens while accusing republicans of conspiracies and plots to sicken and kill black Americans.