Personally, I'd like to see an independent movement, where a significant number of politicians did not belong to a political party, or caucus with one.

Careful what you wish for. I actually think that this is an outside possibility, but only for the reason that I think wealthy individuals might start to bypass parties and buy their own candidate blocs. I could envision Tom Steyer, the Kochs, Sheldon Adelson, etc, each deciding that pary politics are inefficient and dilute their core values. (E.g. why should Tim Steyer care about labor unions, or why should Adelson care about abortion? Currently, their candidates have to pretend to care about a lot of things, when the backer is typically an issue-minded person.) They could, with the current soft corruption system codified into law, take matters into their own hands and start sponsoring "independents," who of course would be "Washington outsiders" who are "beholden to no one".

I hate party politics, but it still might be better than six or seven individuals owning a significant chunk of Congress. With how expensive it is to run a campaign, this is the only way a significant number of independents will ever be elected.