Americans might support DACA, but not to the level where they are willing to shutdown the government over it. The numbers people quote, like 90%, are that they probably are only 90% "sure whatever" when it comes to the issue. Not full on passionate. This is reflected in the current CNN poll where they would rather have government open than care about cheater dreamers.
https://townhall.com/tipsheet/timot...-is-not-worth-a-government-shut-down-n2437156
According to CNN, 56% of Americans would rather the federal government stay open for business than Congress reach a compromise on DACA. "Still, 56% overall say approving a budget agreement to avoid a shutdown is more important than continuing the DACA program, while just 34% choose DACA over a shutdown.
https://townhall.com/tipsheet/timot...-is-not-worth-a-government-shut-down-n2437156