I have a lot of issues with this pairing. Here’s why:
First of all, outside of a few late 1960s Mickey Mouse newspaper strips, there’s nothing to support it.
I’m gonna guess this whole thing started with her portrayal in the movie The Three Musketeers. Okay, fine, she develops a crush on him, but you have to remember an important detail: That movie isn’t the normal setting for Mickey, and they’re basically playing different versions of the characters, much like the featurettes that inspired it- Mickey and the Beanstalk, and The Prince and the Pauper.
Second, just because Clarabelle stands next to Goofy on rare occassions in Mickey Mouse Clubhouse, Minnie’s Bow-Toons, and even Roadster Racers doesn’t really mean anything. I suspect the writers are trying to imply something, but just because they forgot Horace exists and noticed that Clarabelle and Goofy are the same height shouldn’t be a reason to do that.
Third, Clarabelle has had a boyfriend almost since her inception: Horace Horsecollar! Nearly from the day the two appeared in a cartoon together, they’ve been a couple. The newspaper strip by Floyd Gottfredson in the 1930s went to great lengths to reinforce this idea, even going so far as to have Horace ask her to marry him (which, unfortunately, didn’t pan out).
Finally- and this is the most important, in my opinion- Disney made an entire feature film just to give Goofy a girlfriend: Sylvia Marpole from An Extremely Goofy Movie. It irks me to no end that this aspect seems to be almost entirely forgotten. Hardly anybody seems to know she exists, even Disney themselves, seeing as Sylvia hasn’t made a single appearance since the year 2000. That’s seventeen years by the time of this post.
So I really don’t know why the whole Goofy/Clarabelle thing exists. It’s barely even backed up by anything, except maybe by Horace’s absence. It really irritates me.