tornadoes happen when hot air slams into cold air, which is why they happen in transitional periods of the year. so, will climate change produce more tornadoes? well, that depends on if it produces more extreme temperature gradients, and that's a very specific question that is more regional than global.

hurricanes, on the other hand, are caused by very hot surface temperatures over open bodies of water. it is a complicated and dangerous thing to do, as there are so many other factors, but the research that exists does suggest a substantive predictive correlation between rising open temperatures and the frequency and intensity of hurricanes. you can make a very crude but very real connection here: more hot water = more hurricanes. that's legit.

you can't do that with tornadoes, because it's not about the global increase in average temperatures but rather about how large the difference in temperature is between competing air masses.

so, let's say the average summer temperature in your region increases by five degrees celsius, but you still find yourself subject to extreme blasts of winter cold. then, you'd get more tornadoes where you live, as the difference between your hot and cold weather extremes is getting larger, which is what causes the tornadoes. on the other hand, if you live in a region where the winter temperatures increase by a large amount, but the summer temperatures remain moderated by the ocean or something else, then you'll see a decrease in the number of tornadoes.

if climate change works out the way the models suggest, and models have margins of error, then i would suspect that the american midwest would see a decrease in the number of tornadoes, which would get pushed further north into canada. the reasoning behind this is that the higher levels of latent heat in the south would act as a greater buffer for the polar winds. the tornadoes would not stop, they would just move further north. but, the south should not get excited, as that means more hurricanes, instead - and, subsequently, more flooding in the mississippi drainage system.

globally speaking, i wouldn't expect an increase in the amount of heat trapped in the atmosphere to create larger temperature gradients overall, unless it is happening in conjunction with something else (like a solar minimum), so much as i would expect to see a difference in the overall distribution of tornadoes. some areas would see less tornadoes, others would see more; the sum total of tornadoes, globally, would remain roughly constant.

it's one thing to run your mouth off on social media where nobody really cares what you say and whether it's true or not, but you expect a congress person to actually take the time to do some proper research if she wants to actually be taken seriously by actual adults.