No simple answers here. Remember, this is the PRECISE tactic that Bill Clinton used in order to win reelection (substituting "tough on crime" for "tough on immigration", thought) turns out it was wildly popular in the short term and Clinton won easily. And then the reality of offering up a portion of the Democratic constituency (in this case, young black men imprisoned for decades for minor "third strike" possession charges) arose and for a lot of people shattered the illusion that there was a real tangible difference between the Republicans and Democrats. "Everyone is against us, fuck it we won't vote, or even cast protest votes for someone like Trump".
Arguably Trump would not have won his first of even second term if not for that betrayal.
Saying Democrats should "get tough on immigration" is tantamount to saying "immigration is bad" and that's a death knell to the Democratic coalition.
In short Democrats MUST NOT showcase a "tough on immigration" plank, rather they MUST campaigning on "our immigration system has been deliberately broken by vandals who were never interested in it functioning in the first place. We need "start from scratch immigration reform".