Adam Weinstein has a fantastic and highly accurate article about why campaigns from all over the political spectrum continue to plagiarize despite being caught and shamed. This may or may not shock you but the reason political plagiarism keeps happening is because the both voters and the politicians want it to stay that way.
No fucking way you say? It's true.
In the past 15 years, I've worked on six political campaigns and worked for four politicians — two of them Members of Congress. Ripping off ideas and regurgitating are the only ways to keep getting re-elected, keep the donors happy, and keep the party happy. Venturing into the unknown, however desperately needed that is, is too risky. Despite all the vocal unhappiness from people like Weinstein, it's what the people want even though they say they don't want it. (Creepy, I know.)
Anyone who is a fan of a sports team is probably familiar with a very common quote: we won; they lost. It's all about being part of a winning faction but distancing yourself from any negative consequences. Politics work the very same way.
Uncharted territory is very dangerous. If a politician has a plan targeted at eliminating the national deficit, it might sound attractive, but she won't get too many Congressional supporters initially. (If it looks too good to be true, then it probably is.)
Let's say this Member of Congress introduces the bill, and it passes. If the national debt goes away like she said it would, everyone will want a piece of that success. They'll all chime in that they were part of it from the very beginning. They'll claim to know the original bill sponsor back when she was unheard of. If the national debt triples instead, then everyone will be taking a public shit on that politician. Talking heads will wring their hands and say she should have known better. Other Members of Congress will lambaste her in floor speeches and Sunday morning talk shows. They'll tout the fact that they didn't support such a piece of shit idea because they're so damn smart.
Mistakes are ammunition for the next campaign season.
Keeping all those consequences in mind, I'm not surprised at all that politicians gravitate to what they know (polled campaign messages and packaged talking points) as opposed to trying to create their own stuff.
The other issue is the national party committees. Many campaigns are truly beholden to those two behemoths for money, staff, resources, and other support. If you don't stay on party message, not only do you risk losing your seat, but you risk neglect from the DNC/RNC. What's worse is that this pre-packaged messaging often comes from incompetent consultants, who don't know shit, but they get hired over and over again and they peddle the same campaign messages they had in the 1980s or whenver their respective party won control of a branch of government. (Fun fact in the Washington Post article: Mark Mellman, one of the consultants who are responsible for this BS, defends himself by saying that even though he lost some races, a presidential campaign still hired him. Yeah. The Kerry campaign.)
Voters are a fickle bunch. I learned a long time ago that voters will say they want one thing but data will show the opposite is what they really prefer. It's not on purpose or out of ignorance.
Campaign material is diluted and simplified down to about a sixth grade reading level so voters think that problems are a lot easier to solve than they actually are. Voters are also lead to believe issues exist in a silo when in reality some problems, like the labor rights and food production, are very much related to each other.
I totally understand why voters will say they don't feel like Congress is listening. Congress is listening. Congress is listening to the fact that you want bigger and better schools, more sidewalks, safer neighborhoods, lower college tuition, and paved roads but you want lower taxes at the same time. You think that because politicians tell you that's possible.
In addition to figuring out what voters really want (as opposed to what they say they want), and that data can change week to week, it's also about figuring how how they want it done. What do voters keep gravitating back to when polled? The same shit that someone else thought up because chances are good voters are already familiar with it. (See above.)
Voters aren't policymakers or policywonks. It's not their responsibility to sit in a room and think this shit up. What they inadvertently end up relying on is what consultants and politicians present to them during campaign season. (See above.)
Yes, Weinstein is right. It's like one giant turd-covered version of Groundhog Day. But that's how the system works, and its participants (consciously or subconsciously) really do want it to stay that way.