Primary Day has arrived and races in several states are sure to be nail-biters.
ABC's David Muir talks to Politico's Shira Toeplitz about the contests to watch in today's Conversation .
Races in Colorado, Connecticut and Minnesota are going to come down to the wire as some candidates ride the anti-establishment wave that has dominated the political conversation in recent months.
The primaries will also be a showdown of big-name endorsements. Presidents Barack Obama and Bill Clinton have thrown their support behind competing candidates in Colorado's senate contest. Republican superstar Sarah Palin has rallied for her choice in Georgia's gubernatorial race against the candidate picked by Newt Gingrich and Mike Huckabee.
Watch today's conversation for a preview of the Primary Day toss-ups.