Waxman is considered more liberal on issues like climate change, energy and business regulation, and potentially more aggressive on healthcare. Dingell, the longest-serving House lawmaker, is close to the auto industry and autoworkers.
Waxman, as mentioned, is also extremely anti-gun – which means that we could see heavy handed attempts to regulate the gun industry come out of Congress. This is a big victory for Pelosi’s hard-left contingent, as they were able to replace John Dingell as committee chair. Dingell had repeatedly bucked Pelosi on bills and other issues, so I guess that hard left partisan politics eats their own party memebers as well. Too bad.