Democratic senator and top Clinton surrogate Claire McCaskillClaire McCaskillFive takeaways from the Georgia special election Picking 2018 candidates pits McConnell vs. GOP groups Potential McCaskill challenger has .7M: report MORE bashed rival Bernie SandersBernie SandersNRA head: Sanders 'a political predator' What would Bernie say to Wall Street for 0K? Sanders warns of possible nuclear war with North Korea MORE on the day of the Iowa caucus as lacking the foreign policy chops needed to serve as commander-in-chief.
"In some ways, it's tough for Bernie Sanders if he's the nominee. As we get closer to November, people begin to visualize who is going to be the commander-in-chief, who is going to stand for us in a dangerous and complicated world," the Missouri senator told MSNBC Monday night.
She went on to criticize Sanders for choosing not to identify as a Democrat during his time in politics and pushed back against his chief declaration that Clinton was wrong for voting for the Iraq War, a war Sanders voted against.
"Most Americans are going to want a foreign policy that has more depth to it than, 'I was right about the Iraq War vote,' and that seems to be the only thing that Bernie has shown a mastery of," she said.
Clinton allies have upped the attacks on Sanders national security record in the final weeks before primary votes begin. While Clinton still has a slight lead in most polls, Sanders has closed the gap to essentially a dead heat in Iowa.
McCaskill also commented on recent attack ads by Republican groups that Clinton allies believe are actually intended to drive up progressive support for Sanders by issuing backhanded compliments about his policies. The Missouri senator's campaign did something similar in order to buoy then-Rep. Todd Akin's chance of winning the Republican primary because he was seen as the weaker opponent.
"All you have to do is look at Bernie Sanders and realize that the Republican attack machine has not touched him. You have to ask yourself why," she said.
"They would like Bernie Sanders to be the Democratic nominee because Republican operatives and all that dark money that's buying those fake negative ads, they want Bernie Sanders at the top of the ticket for Democrats because they believe they can defeat him."