This is what I came across:
"The Comptroller General's plan to sue the Vice
President raises a host of unresolved legal issues.
As a threshold
matter, there is a question whether the courts will permit a
representative of Congress (here, the Comptroller General of the GAO)
to invoke judicial process against the Executive. The courts often rely
on the standing and political question doctrines to avoid adjudicating
conflicts between the other branches."
I guess it could mean "First (of all)", but want to confirm with it.
Thanks a lot!
Ben