Award Snub: A lot of people think that Jimmy Stewart should have won the Academy Award for his performance as Jeff Smith. Even the Academy seemed to feel guilty for not giving Stewart the award, because they gave him Best Actor the very next year for his performance in The Philadelphia Story, which most people agree wasn't as good. On a side note, quite a few people wanted Claude Rains to win Best Supporting Actor.
Smith breaking down at the Lincoln Memorial after being publicly accused of corruption by the man he admired as a child.
The Woobie: Jefferson Smith. He just wants Truth, Justice and the American Way! But Washington just isn't run that way anymore.
Values Resonance: A tale of corruption in the highest body of law is more relevant in the post-Watergate era than it was in the 1930s.
The speech about the number of hoops a congressman has to jump through or work on to accomplish anything certainly resonates well with viewers after the United States suffered a government shut-down in 2013 simply because Congress was unable to agree on a national budget.
Not Even Bothering with the Accent: Look, Claude Rains was fantastic in this movie (and he was basically unrecognizable under the hair and makeup), but really, did he even try to sound American?