Marco Rubio gave a speech which argues that making it more difficult for mass shooters to obtain assault rifles like the AK-15, which was used to murder 17 students in his state, would be pointless. If we made it more difficult for the 19 year old who used an AK-15 to murder 17 students, it would not have prevented the crime. The shooter would have found an illegal way to obtain the weapon that he used. In other words, there is no way to stop mass shootings by restricting access to guns. Guns are not the problem. Demented individuals are the problem. Rubio's logic would also make it pointless for the government to restrict access to drugs like heroin. After all, drug addicts can often find illegal ways to obtain heroin. We might just as well sell it at CVS. That would make it easier to purchase, and it would reduce the price because illegal drug drug dealers must charge high prices to cover the costs of obtaining heroin and the risks of being arrested.
Marco Rubio is not stupid. He only makes stupid arguments because it is in his interest to do so. Rubio has received over $3,000,000 from the National Rifle Association (NRA) in campaign contributions. He doesn't want to bite the hand that feeds him and other politicians who have been bought and paid for by the NRA. Rubio also understands that the majority of Republican voters in his state oppose government restrictions on access to guns. They see no difference between an AK-15 and the rifles that are used for sport by hunters. Some of them even believe that the best way to protect students in schools from mass shooters is to arm the students so that they can protect themselves. Fox News and popular talk radio hosts like Rush Limbaugh make that argument after each mass shooting.
The bottom line is that many politicians, especially those funded by the NRA, care more about winning elections than they do about mass shootings. They are not stupid; they are immoral. They offer meaningless prayers to those whose suffering they have enabled because they have sold themselves in order to win elections.