Democrat Robin Carnahan’s campaign for the U-S Senate gets a shot in the arm Thursday. Vice President Joe Biden is scheduled to be the headline speaker at a Carnahan. Missouri’s secretary of state is behind in the latest poll. The Rasmussen poll of likely voters shows Republican Congressman Roy Blunt with 52-percent to Carnahan’s 43-percent. Blunt and Carnahan are running for the seat being vacated by retiring G-O-P Senator Kit Bond.