"According to the official results from Florida, Republican Vern Buchanan, won the 13th Congressional District by 369 votes. But DAlesandro can use her power as Speaker to steal that election for the Democrats and install Christine Jennings as the winner and new Congresswoman. The Democrats did that in 1984 over a seat in Indiana. It would be in character for DAlesandro to do that in 2007."
Apparently so: "Pelosi may not seat winner in disputed Sarasota race"
http://www.freerepublic.com/focus/f-news/1757895/posts
She CAN refuse to seat the winner. But, it is NOT up to her to pick a substitute.