I can see how you missed this.
Right under the "Join Dashboard" box, there is a link with the caption:
Already have an account? Click here to log in
If you click that it takes you to a login screen where you can actually login directly with your Facebook account, if you want (many people have a Facebook account, so that would have worked if you choose that path).
Anyway, on that page is the big "Log in to Dashboard" button.
But, seriously, since odd are you have Facebook accounts, it's better to log in that way. They have really good tools to help Progressives make good use of Facebook.
Anyway... I really wish I was more clear before.
And... now that you know how to log in correctly, rather than "The government sure isn't..." and "The government isn't really an X..." posts, I should instead see posts by people who identify the issue and indicate what they are doing on Obama's Dashboard to change things.
I've already started.
If you have any problems logging in, PLEASE direct message me on DU. I'd be glad to help you get started.