Simply lazy on the part of Constant contact to have not implemented a simple feature like this.
Overall,s the new editor is just dumbed down too far to be totally flexible.
I do apologize for any inconvenience not having this feature may have caused but I am happy to report that you now have the ability to remove underlines from links in the third-generation editor. When you click on the "Design" tab in the editor you will see the option to control the font style of links.
We do appreciate your feedback and I encourage you to visit our Feedback area of the Community to post additional concerns or ideas you have and view what other customers are saying as well!
I'm sorry that you have had trouble removing an underline in your email. I took a look at the most recent email campaign in your account and I was able to replicate what you are seeing. There is a link that will not remove the underline when you go through the normal process. When I created a fresh text block and re-created the link it gave me no problems adding or removing the underline, though. Very strange! I appreciate you letting us know. I'll submit this to our upper level of support to see why that may have happened.