Most mass shooters are not really politically motivated. They are just insane! And as such, may pick any item out of the news to justify what they decide to do, or else they’ll just do it without any justifications whatsoever.
About Obama though, he used tragic shootings to motivate Congress to improve ways of keeping weapons out of the hands of madmen — not to take away all our guns or to enhance his career of someone elses! And yes, Sarah Palin got a lot of flack for endorsing the bulls eyes over states where democrats supposedly threatened 2nd amendment rights, so some may understandable describe that controversy as being cut from the same cloth. But Giffords didn’t use the attack on herself and others, as a way to win personal political favors — she used it as a reason to improve gun regulations in ways that might stop shooters like her’s in the future, (just like other Democrats have always promoted improving background checks) — not to vaunt herself very soon after being injured, (remember she had to learn to speak all over again first)? So although both sides may make mountains out of molehills by inappropriately using shootings to make their points, you can’t equate President Obama’s call to improve regulations in response to mass shootings on par with NRA nuts who actually claimed that the Newton massacre was created by democrats just to pass gun legislation?
If you want a better example of an injured Republican who used his experience wisely, then go back and read about Reagan’s former press secretary Jim Brady, who was largely paralysed but fought for the rest of his life to make sure kooks like his shooter, would not be able to do the same to others (on a non-partisan basis). Obviously there is a big differences between the political opinions of those who have never been victims of gun violence, and those who have. Giffords is a Democrat and Brady was a Republican but what happened to Brady also turned Reagan into an advocate for gun regulations. However, apparently Scalise just doesn’t care how brazenly he uses his own shooting just to score personal political point!