For several days now there has been an 'endless loop' problem with logging in into Blogger.
When try to log in or go to Blogger from whatever other Google application, such as gmail, by choosing Blogger from the services menu at the top right of the browser page, it takes you to the Welcome page inviting you to create a blog or log in. When you click login it takes you back to the Welcome page.
The solution here is to go to your Google profile and 'change' your profile (displayed) name. In fact, you don't have to change it, just type it in as it is or was and click go to Blogger. Than will take you to your usual Blogger page with blog posts, stat and all the other stuff.
Here is the direct link: https://www.blogger.com/switch-profile.g