Bowers probably seen Jews as the root of the immigration problem, because many Jews, being immigrants themselves, are compassionate about other immigrants and refugees, so they work at organizations like HIAS, helping people. For example, HIAS can file an appeal, that would prevent immediate deportation of caught immigrant. But the actual root is that Mexico has small salaries, while US has large salaries, so Mexicans want to work in US, and US entrepreneurs support that, while American citizens get mad at increased competition and demand protectionism.
Anyway, that Bowers is just a crazy schizo.