Trump-Bannon feud scrambles key 2018 GOP primaries Bannon has endorsed candidates in races in Nevada, West Virginia and Arizona.

 -- Republican candidates in key 2018 races, many already navigating difficult political terrain, are now dealing with the fallout from the very public and bitter feud between President Donald Trump and his former chief strategist, Steve Bannon.

The rift between Trump and Bannon was blown open this week when Bannon was quoted in a new book on the Trump White House by journalist Michael Wolff making disparaging remarks about members of the Trump family.

Trump criticized Bannon in a statement Wednesday, saying, “When he was fired, he not only lost his job, he lost his mind.”

The open sparring between Trump and Bannon threatens to undermine the former top White House aide's ability to hold together his coalition of hand-picked candidates in a number of high-profile 2018 Senate races.

In October of last year, Bannon told Fox News' Sean Hannity that there was a "coalition coming together" to challenge every incumbent GOP senator up for re-election in 2018, except for Texas' Ted Cruz.

Now members of that so-called coalition are now facing a choice: defend Bannon, or shun him and stand by President Trump.

In Arizona, where Bannon has backed former state senator Kelli Ward in her bid for the seat currently held by retiring GOP Senator Jeff Flake, her campaign sought to downplay Bannon’s endorsement and emphasize the candidate’s support for President Trump.

“Steve Bannon is only one of the many high-profile endorsements Dr. Ward has received. Her focus remains on winning this race, which she is in a great position to do, and then helping President Trump advance an America First Agenda,” Ward’s press secretary Zachery Ward wrote in statement.

In Nevada, where Sen. Dean Heller is the only GOP senator up re-election in a state won by Hillary Clinton in the 2016 election, his campaign is utilizing the Trump-Bannon feud against his Bannon-backed opponent, Danny Tarkanian.

“Danny Tarkanian and Steve Bannon are frauds whose only skill is losing elections and costing Republicans seats,” Heller spokesman Keith Schipper wrote in a statement.

Tarkanian largely stood by Bannon, saying he welcomes his support as long as Bannon backs his campaign against Heller.

"I supported the President before he was elected; I support him now, I will continue to support him after the primary, and most importantly I will support him after I am elected," Tarkanian wrote in a statement, "The same cannot be said about Mr. Heller. And if Mr. Bannon chooses to support me in our effort to repeal and replace Dean Heller with someone who will truly have the President's back, I welcome his support."

In the already heated GOP Senate primary between Rep. Evan Jenkins and state attorney general Patrick Morrisey-- backed by Bannon-- both candidates hurled attacks at the other, with Jenkins calling on his opponent to disavow Bannon’s support.

“After Steve Bannon’s vicious attacks on President Trump and his family, Patrick Morrisey should immediately disavow Bannon’s support,” Jenkins wrote in a statement Wednesday, “If he refuses, West Virginians will know that what President Trump said of Bannon today is also true of Morrisey: ‘he is only in it for himself.” Morrisey later distanced himself from Bannon and his comments, saying he “does not support these attacks.”

“Patrick Morrisey has been endorsed by many conservatives throughout West Virginia and America because of his strong conservative record. Attorney General Morrisey does not support these attacks on President Trump and his family, and was proud to stand with President Trump in 2016 when they were both overwhelmingly elected in West Virginia and when he cast his vote for Trump in the Electoral College,” Morrisey spokeswoman Nachama Soloveichik wrote in a statement.

Following his rift with Trump, Bannon’s role in the 2018 midterm elections is much more unclear.

Senate Majority Leader Mitch McConnell, who saw the already slim Republican majority in the Senate dwindle last month when Bannon-backed candidate Roy Moore lost to Democrat Doug Jones in Alabama, bringing the balance of power in the Senate to 51-49 in favor of the GOP.

Following Moore’s loss, McConnell did not mince words when asked about Bannon’s political acumen.

“The political genius on display of throwing away a seat in the reddest state in America is hard to ignore,” McConnell said in a news conference last month.

President Trump also alluded to Moore’s loss in his statement attacking Bannon.

“Steve had very little to do with our historic victory, which was delivered by the forgotten men and women of this country,” the president wrote in a statement, “Yet Steve had everything to do with the loss of a Senate seat in Alabama held for more than thirty years by Republicans. Steve doesn’t represent my base—he’s only in it for himself,”

The Senate Leadership Fund, a Super PAC run by McConnell allies that invested heavily in Roy Moore’s GOP primary opponent, Luther Strange, also piled on Bannon.

“We have said from the beginning that Bannon would be a liability for any Senate candidate who embraced him, and now that he has openly turned on President Trump, it’s hard to see how his toxicity helps anyone,” it said in a statement.