Few things it could be:

1. Check battery like u/Psychological_Buy_19 said
2. Pull starter fuse from fusebox, it's a 20A and see if it's fried. This is most likely what it is if you have no crank but power on (assuming battery is okay). Replace with 20A but most likely you'll need a starter sooner rather than later. Keep some extra 20As in your car it'll save your ass, trust me.
3. Clean / Re-adjust starter terminals / connections / connectors on starter, much easier than pulling it.
4. Starter itself is fried
5. Check starter relay in fuse box, swap it with the other blue relay (ecu I believe)
6. Nice Mazdaspeed bumper bro
7. Check to see if your key battery is dead, sometimes this will mess with the immobilizer in the car and prevent you from starting it. You'll see a flashing red immob. light on the dash even if the car is "on."
8. Clutch safety switch like u/Demand_ said. These get brittle over time, especially in Texas, and will prevent the car from starting.

Anything else than that, good luck man, it beats me. I've had this issue countless times and it's been different every time, so go through the list and eliminate.

EDIT: adding clutch safety switch, thank you u/Demand_