Here’s a legal hurdle that must be overcome:
“July 27, 2009
I, Dr. Chiyome Fukino, director of the Hawaii State Department of Health, have seen the original vital records maintained on file by the Hawaii State Department of Health verifying Barack Hussein Obama was born in Hawaii and is a natural-born American citizen. I have nothing further to add to this statement or my original statement issued in October 2008 over eight months ago.”
It's not a "legal" hurdle. That was not a sworn statement, it was a press release.