Tomorrow primaries will be held in Colorado, Maryland, New York, Oklahoma and Utah, and we’ll be talking about some of these contests later. But the marquee even is in Mississippi’s SEN GOP runoff, in part because nobody know what is going to happen.

Conventional polling isn’t much help because runoff polls start with the universe of voters who participated in the first GOP primary. Yet Thad Cochran’s entire strategy is to expand the runoff electorate beyond primary participants, most notably by appealing to Democrats. Thus pollster Brad Chism, whose tracking poll has been showing a sharp break towards McDaniels during the last week, admits he and other observers are in uncharted territory:

No Polling Can Measure the Implications of Two Unprecedented Actions in Mississippi Politics

* Surrogates for the 42 year GOP incumbent are groveling for Democrat and union votes in the runoff after his campaign spent millions in the Primary bashing President Obama and his policies.

o Can Cochran’s team execute their elaborate, expensive GOTV plan?

o Will this pivot to a more centrist message erode his conservative base?

* Republican office holders have gotten way out ahead of their constituents

o Are the establishment Republicans able to bring the rank and file to Cochran?

o Will there be a backlash from this top down directive?

What is clear is that Team McDaniel is using the full panoply of race-loaded “voter fraud” rhetoric in trying to build a backlash against Cochran’s efforts to convince African-Americans who didn’t vote in either party’s primary on June 3 to show up and ask for Republican ballots tomorrow. Some of it is based on unsubstantiated rumors of “walking around money”–traditionally funds made available to GOTV street operatives (not in itself illegal) that may or may not be illegally shared with voters–pouring from the coffers of Cochran’s corporate allies into African-American churches and other intermediaries in Jackson and the Delta. And some of it’s based on a deliberately obtuse reading of a Mississippi law that purports to limit participation in party primaries to voters who “intend” to vote for that party in November–a law that would surely be held unconstitutional in the unlikely even it were ever enforced.

What makes the “voter fraud” claims particularly strange, of course, is that no one can seriously claim Democrats are trying to “interfere” in a Republican primary to help choose the most vulnerable rival for the Democratic candidate in November, since it’s widely assumed a Cochran win tomorrow would pretty much end any hopes of victory for Democrat Travis Childers. No, this is all about Cochran appealing to African-Americans based on actual appreciation of his record (understandable in the context of Mississippi) and/or hostility to McDaniel. It’s a tactic that’s not only new to Mississippi, but to the South generally, at least on this scale, and so the backlash is impossible to measure as well.

Word is those intrepid Houston-based “voter fraud” activists True the Vote may send volunteers into African-American areas tomorrow to police balloting. That ought to go over real well, particularly if the TTV folk are going to yammer at voters about the stupid “intent” law. In any event, we can expect some hijinks tomorrow, and the outcome ought to become much more transparent the minute Hinds County and Delta precincts begin to report. Unless turnout is up sharply from the primary in those areas, Cochran’s 42-year congressional career is probably coming to an end.

Ed Kilgore

Ed Kilgore is a political columnist for New York and managing editor at the Democratic Strategist website. He was a contributing writer at the Washington Monthly from January 2012 until November 2015, and was the principal contributor to the Political Animal blog.