To be fair to Leona Lewis, she does have a technically very very good voice, and in my opinion she sings Bleeding Love very well, with emotion, or at least with the impression of emotion.
I do not think however that the song is that special, and no, I am certain it would not be winning this poll if anyone else had sung it. People are voting for her, maybe for her voice, maybe because of all the X Factor hype, and maybe because Simon Cowell has hypnotised everyone in the country via subliminal TV messages, except for Mika and Take That fans, who are somehow genetically immune.