14th amendment to Constitution, supreme law of the land: "nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws." so you are flat out wrong about "all the due diligence they're entitled to", chapter and verse. Hope you can understand the plain English.
Your being pulled over in S Texas has nothing to do with "any person" getting due process... unless you wanted to make a case of it and take it to the courts... I assume it has something to do with probable cause, the why they pulled you over not stated. IF they had no cause you could have won your case which could change the law and get you maybe a tidy sum.
"Not happy with it's been that way for decades" indicates you don't grasp the importance of courts and the Constitution. Slavery was legal & had been that way since 1619 which is basis for amendments.
It is typical for those in power to overstep their bounds trying to get more power... the original concept was that if one branch (executive... Trump) broke the law, failed to abide by Supreme Court rulings (another branch) then Congress would rein him in, by impeaching & removing from office if need be. But he has shown the flaws: stacking the courts, weaponizing the justice department and turning the Republican party members in Congress into a group of cowering sycophants.