[tzs]

That 78% breaks down to something like 90% of Democrats, 80% of Independents, and 60% of Republicans.

Among the Republicans, the 40% who are anti-immigration tend to feel very strongly about it, and are likely to consider it a major issue. The 60% of Republicans who are OK with immigration are less likely to consider it a major issue.

This makes it hard nowadays to get Republican support in the House for pro-immigration policies, because a pro-immigration Republican member of the House will attract anti-immigration primary challengers who will get the vote of the 40% who are anti-immigration. With that big bloc in hand its hard for the challenger to lose.

You can see a similar thing with abortion. About 60% of Republicans favor keeping Roe v. Wade, about 30% want to overturn it, and the rest are unsure [1]. But how many Republican members of Congress will come out or vote in favor of keeping Roe v. Wade? Pretty close to zero because doing so is political suicide in their next election.

[1] https://www.npr.org/2019/06/07/730183531/poll-majority-want-...