Apparently, they were approached by the university's LGBT-rights group to ask to be a co-sponsor of the event. The CRs agreed. Then, under the midst of the Prop 8 trial, she (and her mother) publicly came out for marriage equality.
What do the GW CRs do? They renege on their co-sponsorship and send out a press release about it. I suggest you do a Google search about all of this; I have gotten so many Google Alerts for "College Republicans" related to this story, which I used for reseach, that it is not even funny.
I would suggest you read the press release, it really is quite humorous. First off, I wonder if they could have chosen an even worse title? The release's title says that they were originally for "GW Marriage Equality Week." Next, a gay-rights group approached them for co-sponsorship and they didn't raise an eyebrow? (They claimed that they were duped.)
However, my personal favorite part of the press release is:
Ms. McCain’s views on marriage equality align with neither the Republican Party nor her father’s personal stance. Though we fully supported John McCain’s candidacy for President, we feel that Meghan McCain’s last name is not near as important as the message she advocates.
I had no idea that the GW College Republicans have the authority to speak for the whole of the Republican Party and Sen. McCain.
Meghan McCain, herself, wrote a response to the claims that the GW CRs were making:
Seriously, how many 25-year-old women do you know that have the exact same world view as their 73-year-old fathers? Besides, a simple Google search would have tipped off these young Republicans to my very vocal and active support of LGBT rights and marriage equality in this country.
The rest, I guess, speaks for itself.