Automatically log in to public ideas portal when using SSO

What is the challenge?

Currently on a public ideas portal, there isn't a log in attempt when you visit the page until you click on the button to log in (or are prompted to do so when adding an idea or vote).

What is the impact?

It's an extra click to log in.

Describe your idea

Make the idea portal pick up the SSO session automatically, without requiring that manual click.

This would need to happen behind the scenes, and an error should not be shown if it's not successful -- it should just show the public portal as-is.