that's to kill as many people -- >> reporter: even so, professor robert spitzer, who has studied thetion of guns and politics in the u.s. for decades, says sanders' passed votes could be a political problem as the democratic party moves even further left. >> it kind of stands out as something of an anomaly. many people are puzzled by the fact that the most liberal member of the senate, this one democratic socialist, takes the position that seems at odds with liberalism in america. >> senator bernie sanders. >> reporter: during last month's cnn debate, sanders try toddy fu -- tried to diffuse the issue saying the nra gave him a d-minus rating. that may not be low enough. >> kate, sanders' campaign sent a statement saying as president, sanders would take immediate action to reduce gun violence, including repealing that law that protects gun manufacturers, the law bernie sanders helped pass. fred guttenberg says he's looking for a candidate that doesn't have to explain why he ever voted with the nra. kate? >> important piece. good look, drew. thank you so much. >>> coming up, late last