Not only would it give them a lock on the White House for a generation or more, but it would displace probably two-dozen GOP House seats and two or more Senate seats.
Reagan signed an Amnesty in 1986. Prior to that, California had only voted for a Democrat in one of the previous 11 elections. The first year those illegals who were granted amnesty would have been eligible to vote as US citizens was 1992 was also - not coincidentally - the year the state voted for a Democrat for only the second time in 12 election and has never voted Republican again.
If you like where CA is today, you’re gonna love TX in another decade...or less, should they enact amnesty.
Texas, Georgia, Florida, North Carolina, Tennessee, Arizona