The proposed budget is fundamentally immoral and un-Jewish. The Torah repeatedly admonishes us regarding the importance of taking care of the poor, the elderly, and the stranger. Trump's targeting of social programs while simultaneously spreading alarm that undocumented immigrants may occasionally benefit from those programs (whatever the merit of this claim) embodies precisely the opposite of what the Torah requires.
We are told that "if your brother near you becomes poor and cannot support himself, you shall maintain him; he shall live with you, even when he is a resident alien." Lev. 25:35. In the Jewish tradition, this passage requires us not only to care for the needy as individuals, but to do so as a whole--through the government--because public social welfare can do things that private social welfare cannot. Thus Rabbi Hayyim Soloveichik (1853-1918), interpreting this passage, noted that society as a collective has a responsibility to relieve poverty. Historically, Jewish communities achieved this through coercive levies--taxation.
The second portion of this passage is likewise notable: that the obligation to the poor is not isolated to members of our community, but to "strangers" who live among us--for example, undocumented immigrants. In fact, Jewish writers have expressed specific concern about "measures designed to ensure that the benefits of the [social welfare programs] remain within [the community's] own environs and not spill over into other areas." Part of this concern stems from the fact that such instincts may ultimately lead to the nullification of social welfare altogether, but another part speaks to a concern that it may "degenerate into an obsession and finally take the form of a sadistic contempt for foreigners." Aaron Levine, Economics & Jewish Law: Halakhic Perspectives 111 (1987). To me at least, this sounds eerily familiar.
This is, after all, why Sodom was destroyed. Sanhedrin 109a. Various exegeses therefore expand on its behavior as a community: that its laws allowed its citizens to rob and mistreat strangers with impunity, that it required its judges to ensure that wayfarers leave the city penniless, and that it pruned trees on public property so that birds could derive no benefit from them. Sanhedrin 109a; Pirke d'R. Eliezer 25; Bereshit Rabbah 50:10.
In other words, Sodom was not condemned for tolerating homosexuality, as so many on the Right would have us believe, but rather for the enshrinement in its legal system of a contempt for strangers and unjust neglect of the poor. It is not enough for us to privately donate to charity--though this is also required; we must also ensure that our government operates with compassion for those most in need, even, or perhaps especially, when it comes to the strangers who live among us.