Recently, based on Beltway sources, I reported that the odds on the outcome of Trump's latest DACA Dalliance were:

1. Disaster (Some version of the Flake-Durbin-Graham bill, which is basically a Gang Of Eight-type Amnesty): maybe 40%.
2. Deadlock. Congress is simply unable to pass any legislation: maybe 40%
3. Triumph (Sort Of). a limited Amnesty in exchange for some real patriotic immigration reforms: maybe 20%

My instinctive preference: deadlock. Then ICE could start deporting the DACAns and GOP/GAP could run on patriotic immigration reform in the fall mid-terms. But the combined odds of some sort of favorable outcome were quite high—60%.

Trump's Thursday proposal is generally regarded as disastrous by Beltway immigration patriots and it's shifted their assessment of the odds: to Disaster 50%-Deadlock 50%. Hope of getting actual patriotic immigration reform through this Congress seems to have evaporated.

Why is Trump doing this? The most obvious explanation—he really wants a wall, among other things. And in fact he's surprised sensible observers by how far he's moved Democrats on the issue e.g. Democrats should give Trump his wall if it means Dreamers can stay, by Victoria M. DeFrancesco Soto, NBC.com, January 24, 2018.

What will happen? As usual with Trump, no-one really knows—but we've been here before, many times. Plus the Democrats are reacting with their usual arrogant intransigence—which is maybe what Trump was plotting all along.