Re: "Case closed"

Originally Posted by
Odessa Dawn
"America needs a proven leader with a plan — one who thinks big and can bring all parties together. There’s only one such man in this race, and it’s Mitt Romney. Case closed."
More: PRIEBUS: America needs Mitt Romney
Does case closed mean much more has been said or nor more details needed?
More so, 'end of discussion'. It's a forceful way in saying, the opinion given is the only opinion.
I'm not a teacher yet, but I am studying a Bachelor of Education with an English Literature major at Charles Sturt University, in NSW, Australia.