Because the majority of naturalized Latino immigrants, those who followed the law and immigrated here legally, do not want illegal Latinos to be able to come here illegally and remain here.
https://www.pewresearch.org/short-reads/2021/04/20/most-latinos-say-u-s-immigration-system-needs-big-changes/
A relatively high share of Latino immigrants who are naturalized citizens prioritize policies that restrict illegal immigration, even when compared with Latinos born in the U.S. More naturalized citizens than those born in the U.S. say it is a very important immigration policy goal to increase security along the U.S.-Mexico border (56% among naturalized vs. 39% for U.S. born) and establish stricter policies to prevent people from overstaying their visas (47% vs. 35%).