[Theoria]

It doesn't work:
'E-Verify allows politicians to have it both ways: Supporting it makes them look tough on illegal immigration while the fact that it’s so easy to evade means their local businesses and economies are largely unaffected. Thus, politicians who support E-Verify get the political benefits without their constituents paying the economic costs. (Undoubtedly, there are some politicians who support E-Verify because they think it will work, but conviction is greater when principle is cheaper.)'

[usurper]

It doesn't work:

If it doesn't work why are the dems and open border republicans completely opposed to it?

Because its a game changer and they know it. Trump even offered them DACA in exchange and they still said no.