My elderly mother is constantly reading religious / political material and hearing news on tv and radio. she gets very emotional over her views and beliefs and it leads to arguments. what should i do?

Difficult: If this is a change in behavior, she may need an evaluation with her physician. Some agitated depressions can present this way; even some early dementias. Is she insisting that you change in some way? Does she have other social connections beyond tv and radio personalities? Loneliness is a great problem with our elderly especially. You might encourage her towards other ways to spend her time.

Broader view: It occurred to me to try to see another side. Certainly arguments need to be softened into discussion, but it might be possible to turn this into a means of broadening views. Can you imagine a gentle probe - like this? "i'd like to hear what you think, but first calm down so that i can understand you better. Then maybe i can explain my point of view too." it may be a + that she cares about issues.

Politics & religion: With age, religious & political beliefs can become more fixed or paradoxically revert to childhood indoctrination. The problem may be more social: Unscrupulous media e.g. Fox News, Breitbart, Infowars etc. deliberately lie, slant & misstate in order to provoke fear, distrust, divisiveness, extremism, xenophobia, anger, paranoia & illusions of isolation. Why? For money. Get your mom off them.