When the root philosophy engaged by “opponents” includes admission of overt racism as a primary component of its motivation, attack of that philosophy is justified.
Would it make a difference if undocumented aliens currently residing in the country “could live legally and without fear in the U.S.,” but not be offered a special path to citizenship? (
NOTE: Absence of citizenship would prevent them from voting.)
American citizens are free to exercise their respective variety of ethnicity, culture, and values. If other varieties of those elements are subsequently incorporated into the citizen population, American citizens will continue to be free to exercise their respective variety of those elements. There is no reasonable expectation that all Americans are, or should be, homogeneous.
And the laws currently grant that right to a million or so individuals per year, which is generally understood to be beneficial to the wellbeing of the nation.