The methodology of the study that determines that both Republicans and Democrats are roughly equally susceptible to conspiracy theories is a little suspect - a lot depends on which theories the authors decide to test. But two of the questions that they evaluated were specifically Jewish conspiracy theories, and their results show that the self-described Left and Right are equally likely to believe them.
The two questions that are explicitly Jewish conspiracy theories are:
The official account of the Nazi Holocaust is a lie and the number of Jews killed by the Nazis during World War II has been exaggerated on purpose.
A powerful family, the Rothschilds, through their wealth, controls governments, wars, and many countries' economies.
A slightly larger percentage of Republicans (it looks like 1%) believed these conspiracy theories compared to Democrats.
And, if anything, partisanship seems to make one more likely to believe antisemitic conspiracy theories. A significantly lower number of independents believed either of these theories.
A 2020 survey showed that 23% of young Americans 18-39 think the Holocaust is a lie, but it didn't break down the percentages that believe that by politics, religion or age.
At any rate, anyone who claims that their political opponents are more likely to be antisemitic - even when discussing classical, not new, antisemitism - is being blind to the problems in their own side. And when either side uses antisemitism as a political football to attack their opponents, and ignores it on their own side, it shows that they don't really care about antisemitism to begin with.
