Similarly, just 15 percent say they support deporting all illegal immigrants, and just 34 percent favor a border wall — both numbers lower than just about any poll we've seen.
The 15 percent who favor mass deportation is in contrast to the 79 percent who instead favor a pathway to citizenship with background checks. Previous Post-ABC polls asked a different question — whether people would support or oppose an effort to deport all illegal immigrants (with no alternative named). Back in March, 36 percent supported this approach.
Previous Gallup polling showed about 20 percent generally favored deporting all illegal immigrants. But that poll offered a third, middle-ground option of allowing illegal immigrants to remain in the United States and work for a limited time. That might have depressed support — at least somewhat — for mass deportation.
Like Gallup, the Public Religion Research Institute has long asked a similar three-way question and has only once seen support for a deportation-only approach dropping to 15 percent.
Given the varied questions, it's not clear that support for mass deportation is at a new low, but at the very least, it appears that it hasn't increased at all during Trump's campaign and might even have fallen.
And it wouldn't even be the only immigration-related issue that isn't trending Trump's way. Another proposal is Trump's border wall. Last month, the Monkey Cage looked at polling on support for a border wall — which the newest Post-ABC poll showed people opposed 63 to 34 — and found a number of polls showing support for the wall on the decline.
The decline is even more severe when you consider polling earlier this decade showed a majority supported a border wall.
And here's the key point: The Monkey Cage's Michael Tesler noted that the decline was largely among people who didn't like Trump coming around to a position that he strongly opposed. In other words: They appear to have been turned off by his hard-line approach, and joined the other team.
The new Post-ABC poll also suggests this effect might have played a role.
The 64 percent who say immigrants strengthen American society — a new high in the 2016 campaign — is spurred by an increase in Democrats (up 14 percent) and independents (up 12 percent) who say they agree with that statement. The increase among Republicans is smaller.
All of which suggests Trump's polarizing approach to illegal immigration may be having the opposite of its intended effect. It may not be damaging Trump's campaign in a direct way — but it does appear to be helping immigration reform activists rally supporters.