My concern is what happens if a block of people start to become disenchanted with UBI. Will the State cut their funding? Can the State, as the sole employer, lock the group out of the political discourse?

In general I'm not a fan of going to the United States government hat-in-hand. Look at Scotland. They do that with the Brits. They're kicked around all the time.

Here's an example. South Dakota v Dole, the Supreme Court said the government could tie general funding to states to enacting state laws. In this case the states had to raise the minimum drinking age to 21 if they wanted road funding. What's to stop the government in a UBI world, from putting different life-rules on its people.

The government goes from working for the people to providing for the people. That's a massive power imbalance. I don't know of any government I want to give that power. I do know it's not the United State's.