(They don't have cable. Yes, I am my father's daughter.)
For example, The Chris Matthews Show is aired at 6:00 am on Saturday mornings. Other Sunday political shows, like This Week with George Stephanopoulos and Meet the Press, are regularly interrupted. The local affiliate will cut away to a commercial mid-sentence, usually when the guest or panelist is offering an opinion counter to the views of the station. Presumably, the stations are just trying to protect their audience's delicate sensibilities.