The consensus on both ends of the political spectrum over the past 30 years is that public education is a failure and must be abolished through either defunding or diverting funding to charter schools. Providing more funding to public schools would undermine that goal.
I don't see it as a consensus when there has been a systematic defunding and destruction of many many education systems, especially in rural america and the inner cities. It's like saying, why did you fall in the hole I dug in front of you?
I think the GP is arguing from results, not policy. If the past 30 years have consistently resulted in the same policies of defunding and deconstruction, there's apparently a tacit agreement among all parties that that's the way to go.