This is such unexpected news; although I would be cautious to say that Nevada could be a competetive race, it certainly shows that Ensign is not as safe as originally thought. I read an article in The New York Sun about Carter's campaign, he recently toured the Northern parts of Nevada where Kerry got 30% and Bush won 90% in some counties and precincts. He is campaigning as a populist in the mould of his father's 1976 campaign. Apparently, in this political climate people are responsive to Democrats more than ever and Nevada, as a swing-state should be at least competetive this year.
http://www.nysun.com/article/37141