I agree with most of what you are saying.

I still think there was a large institutional bias in favor of the Tea Party's agenda (the small government and deregulation parts especially), the powers that be were all too happy to facilitate such changes, whereas the left's reforms go more directly against the grain of power.

I don't know a lot about the dynamics between the Tea Party and the more established wing of the Republican Party, so won't comment.

I sure don't know how you get corporate money without the influence, so I disagree with you there, I think their money is intrinsically a corrupting influence and will no longer support any candidates who are taking it.

If we could modify the corporate charter so that their main responsibility was to the public good (a vague and undefinable concept but a necessary one) rather than to maximizing profits for their shareholders, then that wouldn't be true anymore. I have no idea if such a modification is even possible. If it is, it would be a great reform to push for.

From my point of view, the Sanders supporters were and are exactly what you're talking about, we have resolve, energy, and are more than willing to give everything we have to effect the changes we so desperately need.

There is a seemingly insurmountable corporate capture of our party leadership, so personally I feel like the party has chosen its side, and it isn't with the people. It would be much better to work for reform of the party, as you say there are huge obstacles to creating a viable third party, but at this point I can't see making any real progress from within the Democratic Party, it will be firmly in the hands of corporatists for the foreseeable future.

I hope many people such as yourself will continue to work within the party to make it better, and good luck with that, you will need it. I will keep my eyes open to see where the rightful home of the energy behind the Sanders campaign is, too early to tell right now.

edit to add: I kind of missed responding to the main point of your post, which is that you would like to see a Tea Party equivalent for our party. I am all for it, long overdue. As I said earlier, I think it will be much harder to do in our party with our issues, but if it could be done it would be the shortest distance between where we are and where we need to go.

Do you want the left to do what the Tea Party did, or are you knocking the part of the left that won't go along with the corporate agenda?

The Tea Party was not just a grass-roots thing, it was Koch-backed, so there's that. If you remember as I do, the news media amplified everything they did, much as they did Trump, giving them legitimacy they shouldn't have had. The reason being that the corporate money people are quite happy with a libertarian vision where government does little more than military and police, and gets out of the way of regulating corporate activities. Just more corporate capture.

There was also a grass-roots element to the Tea Party, but if it was only that, they would not have had the success they had. They served the interests of the powerful, and that's why they had such success.

There is no similar context for those of us on the left. What we want is to get corporations out of our government, to get our military out of most of the nations on earth. to get corporate-pushed carbon out of our atmosphere, and to get non-violent offenders out of prisons. Where is the institutional alliance for this set of demands? There isn't one. People want these changes, but profit-driven institutions do not.

I personally don't think the left has the clout to deliver the change we need in the time we need to do it (climate change being the most urgent driver). I think populists on the left and right need to put our differences aside enough that we can ally against runaway corporate capture. The divide and conquer strategies of the powers that be are very effective, and allow continued exploitation as the world crumbles.

So I would like to see a new entity emerge that rejects any corporate money in campaigns, and that has a narrow platform targeted to issues that don't split left/right. We have enough people and motivation to do this if we can get together with people on the other side, and with the more than 40% who have withdrawn from either side out of disgust for both of them.

Most of the urgent issues of today are not left/right issues. they are top/down issues. We can still work on left/right issues but should not let that get in the way of allying with populists all across the left/right spectrum for the cause of ending corporate capture, ending the support of the American (really a stateless corporate) empire, and immediately doing everything possible to fight climate change and transform our society into a sustainable one that proves good decent lives for its citizens rather than one that is essentially a vehicle for concentration of power into a few hands.

I will always fight for the issues of the left, I just think right now we need to get a few critical things done to even have any kind of inhabitable planet in the future, and we need to work with everyone who is willing to join in such an effort. It's too big of a crisis to leave to the left, we need everyone, and even then it won't be easy, since we'll be fighting every powerful institution. Tear down the left/right wall.