No, it's not political at all. It's just how the system works. Counties use that collected revenue to supplement deficiencies in the county budget, in a variety of applications; for instance, funding driver responsibility courses, supplementing the costs of maintaining inner county roads, road shoulders, mowing, etc.
Here's just one example of how dependent the counties have become on that revenue source; Two years ago the State of Texas passed a law decriminalizing the possession of marijuana in small amounts leaving it to the discretion of the officer at the scene as to whether to issue a citation, make an arrest, etc if the situation involves that substance. There's more to it but that's the basics of it. Once that law made the news and hit the headlines, the DA of Kaufman County, Texas issued a public statement saying that in his county, despite the new State law, anyone found to have any quantity in their possession would be arrested, charged with possession, and they would pursue conviction. He made it clear in his statement that despite the new law, and whether or not the county won the case their goal was to continue collecting those funds thru the plea bargains and associated fines because the county needed the revenue.
It's the world we live in now. Cameras everywhere and law enforcement assuming that if you are behind the wheel during the hours of 12am and 4am then you're either under the influence or up to no good, therefore they are looking for any reason to pull you over. Not because they enjoy busting stoners, but because there's big money in it.