The reason they don't want to answer this question is the same reason Republicans don't (or can't), because it's never going to be 'enough'.
For an example of this take a look at this month's education round-table in Texas Monthly magazine. I'm referring to one small blurb that I'll reproduce here. You should really go read the entire back-n-forth to see just how far apart both sides really are on this issue. The quote I'm referring to cam from Center for Public Policy Priorities Executive Director Scott McCown:
I want to have a strong educational system that produces folks who can be entrepreneurs and small-business men and get out there and make money. If we make he wise investment now, we come out ahead. So I'd expand the sales tax base with some way to deal with regressivity. I would expand our business tax and fix the structural deficit. And in the long run we need a personal income tax in this State.If you're not familiar with the CPPP (and if you read the State's political media there's a good chance you're not) the CPPP is a progressive organization that advocates progressive solutions to what they believe are the State's problems. Typically, in the MSM, you'll see them identified as "a think tank who advocates for the poor." That's not entirely true. The advocate for Government solutions, at taxpayer expense, that ostensibly benefit the poor (despite the fact that there's little evidence linking many of their proposals to an actual decrease in the poverty rate.)
The problem that progressives are experiencing right now is that the money well is dry. Even Texas, who traditionally has resisted big tax and spend legislative solutions to problems that may, or may not exist, is feeling the sting. The progressive answer that tax increases are the solution to Texas' many problems is not being supported by the laboratory of real life.
The big problem with both sides of this argument is that they ignore the real issue here...the fact that neither cuts or tax increases are the solution to the problem. Neither is the "balanced approach" that many are touting as some bi-partisan scheme to make things rosy. Most of the balanced approaches don't cut nearly deep enough, and they raise taxes entirely too high to cover basic needs, instead keeping several political favors to preferred constituent groups and financial backers.
Cuts are, at best, a temporary solution to a long-term problem. Belt-tightening only goes so far. The best solution is to cut temporarily while doing a top-to-bottom scrub of what's not working, what's duplicated and what fat can really be cut.
Unfortunately, when that second, most serious, option is given serious treatment the defenders of the dysfunctional status-quo throw a fit. Never mind that throwing money at a broken model is a bad idea, there are sacred cows that cannot be slaughtered.
Fixing Texas education system is going to take more than just tax cuts or increases, it's going to take serious people making serious decisions about what we're doing right and wrong. Unfortunately, if the current tenor of the debate is any indication, our current leaders are failing education reform 101.*
*This is not to say that the State's think-tanks are not doing any better. The CPPP does nothing more than provide psuedo-intellectual cover for the State's foundering progressive/Democratic, statist-solution minority, while the TPPF is frequently asleep at the wheel on large issues, and doesn't do enough to engage that a State political media that has little interest in seeking out there side of almost any issue.