The popular vote they are talking about is the national popular vote. Right now, as it stands, the electoral votes go to the person with the state popular vote, under this proposal the electoral votes would go the candidate who wins the national popular vote. In 2000, if all states subscribed to this method, Gore would have won.
Fortunately, this is only in CA, and one other state, and ALL states have to agree to this before it takes effect nation wide. Even then each state could change it's mind and give the electoral votes to whomever they wished, just as they can now.
Actually, it's in process in several states.
From NationalPopularVote.com:
NATIONAL POPULAR VOTE LEGISLATIONCalifornia Assembly AB 2948—Assembly members Tom Umberg (D), John Laird (D), and Merv Dymally (D). (AB 2948) .
Colorado Senate SB 06-223—Senators Ken Gordon (D), John Evans(R), and Lew Entz (R) (SB 06-223)
Illinois House HB 5777—Representatives Robert S. Molaro (D) and Jim Durkin (R) (HB 5777)
Illinois Senate SB 2724—Senators Jacqueline Collins (D), Kirk W. Dillard (R and Du Page County Republican Party Chair), James T. Meeks (I), and others (SB 2724)
Louisiana House HB 927—Pre-Filed March 17, 2006. (HB 927)
Missouri House HB 2090—Representatives Robert Johnson (R) and Jeff Roorda (D) (HB 2090)
New York Assembly A11563 — Assembly Members Fred W. Thiele, Jr. (Republican, Independence, Working Families), Jim Bacalles (Republican, Conservative), Joe Errigo (Republican, Conservative), Andrew Raia (Republican, Conservative, Independence, Working Families), and Teresa Sayward (Republican, Independence, Conservative). (A11563)
In 2000, if all states subscribed to this method, Gore would have received 100=percent of the Electoral College vote, because Gore WON the national popular vote.
In other words, I'm not sure why Florida would have made any particular difference. Every state, regardless of its individual outcome, would have given its Electoral College votes to Gore because Gore WON the national popular vote by 500,000.