Um....
You see, the point is they do have funds. They have huge amounts of funds. They have funds coming out their frigging ears.
California, as just one example, is spending TWICE the amount per pupil that they were spending in 1970, in constant dollars, and for measurably worse results. For the United States as a whole, the multiplier is more like 2.4 times the amount. For some states, like New Jersey, it's over three times.
They are wasting the money, and failing to deliver results. When some idiot legislator tells you the reason the schools are failing is lack of funds, he is lying in his teeth.
If the education system was run by a private corporation you'd want their heads on spikes.