I won't comment on the technical aspect, you probably did the best you could in the conditions with your equipment.
What I would comment on is the fact that your title is "U.S Congressman Speaking", I don't actually see a lot of speaking going on. I know you've mentioned it but I really did expect to see someone speaking. I was hoping to see someone stood at a podium
passionately giving a speech, I would have expected to see him mid-sentence visibly projecting his voice. Instead he looks quite glum.
In photojournalism, which I would call this, the image has to tell a story. The impression I get from this image is he has given his speech and has recieved a bad reaction.
I think what would improve it is to catch him at peak action, same with any sport or action-based activity, you need to catch the exciting part. If you want to catch a certain look like of triumph or despair then you need to do the same thing.
Here is a contact sheet of a speech given by Margaret Thatcher, British PM in the 80s, shot by a Magnum photographer. It might just be of interest to see how the best of the best do it.
I have shot stuff similar to this, we had some Royalty turn up on campus, and it really is about capturing emotion whatever it is. Your congressman displays little emotion whatsoever.
The focus on this shot the first shot is way off but my point is I was the only photographer there to get this shot as he was leaving. He's mid-action, that's where you want him. The second shot shows some emotion and the video man in the background creates a form of context and importance. You might get the feeling that he was genuinely pleased to be there. (P.S I don't know what's gone wrong with the colours).
Disclaimer: Feel free to ignore anything I might have said; it's just opinion. I'm not looking to start an argument.