The Next Prez looked at the number of blogs mentioning the candidates and rank ordered them. What I find even more impressive is that Chuck Hagel topped most of the candidates that announced they were running this month.
The leading site for tracking blogs is Technorati and here's a chart from them of Chuck Hagel in blogs in the last 30 days:
Posts that contain Chuck Hagel per day for the last 30 days.
Get your own chart!