The problem is that few of these people feel directly touched by patent issues and that is certainly the case for their constituents. For the average citizen patents are far removed from their daily reality. This means the issue has little political power. And this is probably true across all political alignments.
It's a lot easier to get political movement on things that aren't headline political issues where politicians are handcuffed to a certain stance by past statements/promises/party policy.
That's why we get patent reform changes much more easily than changes around taxation, gun control, abortion rights, education, healthcare and so on.