My family is nearly all teachers, including my wife. I volunteer teaching ESL 4 days a week at a title 1 school nearby. Here in the Houston area, we can't find enough teachers, let alone good ones, even with a starting pay of $55,000 a year. There's never enough ESL, SPED, Math and Science teachers to fill the needs. Some districts have been given the okay to use non-certified teachers to fill the holes. Others use permanent subs.
It's a mess. I could go into the many reasons why it got like this, but funding for public schools has not gone up in Texas since 2005, and they have such archaic laws that communities can't up the taxes to pay for the needs.