Logan Mauldin’s review published on Letterboxd :
I get that this is a classic, and I understand why. Capra has laid the patriotism on very thick. The bright-eyed optimist of Jefferson Smith played by the legend Jimmy Stewart is a character for the ages. The problems, however, come pretty quickly.
The Washington sight-seeing montage was far too long and didn't really add anything to the story with its stock footage. There is very little character development even for Smith. He's introduced by the Governor's kids as some kind of superhero and through news clippings but we don't really see him do anything but bumble and get set-up for failure. And in the end, he really does fail. Multiple times. Finally, the conclusion rushes in and it fades to credits. There is nothing done to bring us to a really satisfactory conclusion.
He's still lying on the floor, we don't see what happens to the bad guys (who are video game boss level bad). All those kids that got hurt defending him don't get any resolution. There's no romantic resolution. It just feels like it was cut short while the filibuster dragged on. There was some very good dialogue and the passing of time was shown well, but it could have been edited more tightly and since they were already using the press for narration anyway it wouldn't make any difference whether they jumped forward a couple of hours or a couple of days at a time.
Ultimately, I enjoyed the movie and I think its message is still needed today, but it didn't do enough to bring it home in the end and left me wanting. I wouldn't mind seeing a remake with updated themes and characters.