A new PMI poll in Mississippi finds Sen. Thad Cochran (R) in a very close primary race with Chris McDaniel (R), leading his challenger by a razor-thin 42% to 41%.

Most interesting: “Indeed, the possibility of a June 24 runoff forced by a third spoiler candidate, Thomas Carey, looks increasingly likely. However, twelve percent of voters are still undecided at this late date.”

Herman Cain, “who at one point topped all Republican challengers during the 2012 Republican presidential primary before dropping out amidst allegations of multiple affairs, suggested on Saturday that he would return to the campaign trail in 2016 if called upon God to do so,” the Huffington Post reports.

Said Cain: “I do not know what the future holds, but I know who holds the future. And I trust in God.”

A Des Moines Register poll in Iowa finds Joni Ernst (R) leading the Republican U.S. Senate primary with 36%, followed by Mark Jacobs at 18%, Matt Whitaker at 13% and Sam Clovis at 11%.

A new USC Dornsife/Los Angeles Times poll in California finds Gov. Jerry Brown (D) “holds a commanding lead in his bid for an unprecedented fourth term, but the race among GOP candidates seeking to take him on in November has become a dead heat just days before Tuesday’s election.”

“Half of Californians deemed likely to vote in the primary supported Brown’s reelection. Among his chief challengers, both Republicans, Neel Kashkari was far behind at 18% and Tim Donnelly trailed at 13%. The difference between the two vying for the second slot in the general election was within the poll’s margin of error.”

A new Rasmussen poll in Pennsylvania finds Tom Wolf (D) way ahead of Gov. Tom Corbett (R) in the governor’s race, 51% to 31%.

“Defusing a tense and potentially campaign-changing challenge from the left, Gov. Andrew Cuomo secured the endorsement of the Working Families Party on Saturday night, easing the popular Democrat’s path as he runs for re-election and solidifying his broader political prospects,” the New York Times reports.

“After weeks of negotiations and last-minute tribulations, Mr. Cuomo was able to mend rifts created by some of his centrist policies and ease the concerns of Working Families, a small but influential group of labor unions and liberal activists. In doing so, the governor — a savvy politician with rumored presidential ambitions — simplified a re-election campaign in which he hopes to win by a large, message-sending margin.”

“In her final weeks as secretary of state, Hillary Clinton wrote a private memo to President Obama warning that relations with Russia had hit a low point and the heralded ‘reset’ in relations was over, according to people who saw the document,” the Wall Street Journal reports.

“Mrs. Clinton, if she runs for president, likely will lean heavily on her experience as the nation’s top diplomat. Her memo, written in January 2013, illustrates two striking features of her four years in the post: She was often more hawkish than the White House she served, and at some key moments was ineffectual at swinging policy her way.”

A new Harper Polling survey in Mississippi finds Sen. Thad Cochran (R) leading challenger Chris McDaniel (R) in the Republican primary by five points, 45% to 40%.

A new Chism Strategies (D) poll finds McDaniel leading Cochran, 46% to 44%.

New York Gov. Andrew Cuomo (D) “is responding to a rebellion from the state’s progressive third party by attempting to push other Democrats away from the Working Families Party,” BuzzFeed reports.

“Cuomo’s move is an escalation that raises the stakes on both sides of the ideologically charged battle, one that has brought to the fore the New York governor’s growing rift with the state’s left. Cuomo political aide and longtime enforcer Joe Percoco has, the sources said, made the request, which is aimed at threatening the party’s ability to get the 50,000 votes for governor in November’s election required for a permanent slot on the statewide ballot.”

Meanwhile, Harry Enten looks at how polling in three-way races is very unpredictable.

“Republican candidates have begun to retreat in recent weeks from their all-out assault on the Affordable Care Act in favor of a more piecemeal approach, suggesting they would preserve some aspects of the law while jettisoning others,” the Washington Post reports.

“The changing tactics signal that the health-care law — while still unpopular with voters overall — may no longer be the lone rallying cry for Republicans seeking to defeat Democrats in this year’s midterm elections.”

Wonk Wire: Have those dire predictions about Obamacare materialized?