In the vote to authorize the Iraq war, precisely one Republican senator came out against it. His name was Lincoln Chafee, now a Democrat running for president, and that vote is why he "could prove Hillary’s most intriguing challenger," writes Peter Beinart at the Atlantic. Beinart doesn't think Chafee has a prayer at winning the nomination, but Chafee will go after Clinton with the argument that anyone who voted for the war—as she did—doesn't deserve to be president because of the mess it has unleashed.
"He will talk about the collapse of Iraq and the rise of ISIS in a way she can’t," writes Beinart. This may not be a problem for Clinton in the primary because national security isn't a big issue for Democratic voters in this election. But it is for Republicans, who blame the Obama administration for bungling the war's aftermath. For Clinton, "if there’s one policy question that could prove dangerous, it’s Iraq," writes Beinart. "On that subject, Lincoln Chafee is the canary in the coal mine. If Hillary can’t find an effective answer to his attacks, it may be a sign of trouble ahead." Click for his full post, or to read about a more unusual campaign platform from Chafee.