It would prohibit Congress "from providing income tax breaks for people earning over $1,000,000 a year, unless we are running surpluses (those surpluses must also not be eliminated, if such a tax break were enacted)." That provision is socially divisive, profoundly partisan, and almost certainly in conflict with the Fourteenth Amendment.
The Udall Amendment is not a serious effort to address a serious problem, but rather an exercise in the worst kind of political cynicism: a vote purely to provide political cover to senators who are in tough fights for re-election next November and who want to be able to claim that they voted for a balanced budget amendment. They want to pretend to be in favor of a concept that the public overwhelmingly supports, while all along knowing that the Udall amendment will fail because it is so fundamentally fraudulent that no senator who really wants to balance the budget would ever vote for it.
There are effective ways to balance the budget, ineffective ways, and bogus ways. Udall's proposal is a bogus balanced budget amendment that should be exposed for the act of political deceit that it is. Anyone who wants a balanced budget amendment with teeth should be for the Hatch-Lee strong version - and only that good version.