Washington (CNN) The next step in Steve Bannon's scorched-earth war against Republican incumbents is an attempt to cut off money to those aligned with Senate Majority Leader Mitch McConnell.

The former chief strategist in President Donald Trump's White House spent the weekend in Connecticut meeting with top Republican donors, a source familiar with Bannon's plans said, as he recruits financial support for enough candidates to nationalize an anti-establishment message in 2018 GOP primaries.

He's held similar meetings in New York City and Washington, speaking with more than 25 major GOP donors so far, including hedge fund manager Scott Bessent, energy executive Dan Eberhart, private equity firm CEO John Childs and mega-donors Robert and Rebekah Mercer.

It was a continuation of what he's done every day since September 26, when the Bannon-backed former judge Roy Moore ousted Sen. Luther Strange in an Alabama Republican primary: Hold meetings to recruit candidates and form a donor network to back them.

Bannon's raison d'etre is to take on McConnell and nationalize Republicans behind Trump.

His thinking -- evidenced by the Senate's failure to advance Trump agenda items like health care -- is that Washington Republicans do not support Trump anyway. So 2018 could be a defining moment, shaking up the GOP and placing Trump's 2016 campaign agenda at its forefront.

What Bannon is seeking from prospective candidates, the source said, is one simple pledge: That they won't vote for McConnell as Senate majority leader.

Bannon's recruiting efforts have intensified over the last two weeks. He is now looking for candidates who can replicate Sen. Mike Lee's stunning ouster of former Sen. Robert Bennett at Utah's 2010 Republican convention next year against Sen. Orrin Hatch. And he is in contact with allies in Nebraska seeking a candidate to take on Sen. Deb Fischer.

And that's "just a partial list," the source familiar with Bannon's plans said.

"Nobody's safe," the source said.

Already, he had spoken with Erik Prince, the Blackwater security contractor, and GOP mega-donor Foster Friess about running against Republican Sen. John Barrasso in Wyoming.

Bannon has also backed Kelli Ward's effort to oust Arizona Sen. Jeff Flake. He hosted Danny Tarkanian in Washington to discuss his campaign against Sen. Dean Heller in Nevada. And he met recently with Mississippi state Sen. Chris McDaniel about taking on Sen. Roger Wicker.

McDaniel, who said he is strongly considering running against Wicker, said Monday that he and Bannon have been in regular contact since 2014, when McDaniel came close to unseating Sen. Thad Cochran. Support from Bannon is helpful, McDaniel said, with strong Trump supporters who know Bannon was a leading figure on the President's campaign and with those who read Breitbart.com, where Bannon is a top executive.

"You factor in the big news he made in 2016," McDaniel said. "You factor in his drive, his work ethic -- and people sense a winner and understand he can bring resources to bear, whether it's Breitbart or with financial resources."

Bannon also plans to get involved in the primaries in West Virginia and Missouri, two of Republicans' top opportunities to pick off Democratic-held seats next year.

The plan, the source said, is for these Bannonites to nationalize their 2018 message with a consolidated, consistent argument across the map.

Bannon wants that message to be about "big things" -- that the grassroots Republican voters are in control and that they don't need the establishment's money or what he views as its corruption.

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Avoiding another O'Donnell

Bannon, the source said, believes his insurgent slate will be different than the tea party calamity of 2010, when flawed candidates like Christine O'Donnell in Delaware and Sharron Angle in Nevada cost the party seats, or 2012, when Todd Akin in Missouri and Richard Mourdock in Indiana made controversial remarks that swung their races in Democrats' favor.

Instead, Bannon, the source said, is recruiting candidates who are focused on substance -- particularly immigration and trade -- and could win over a loose coalition of social conservatives, tea party activists and values voters.

The test case was Alabama, where Moore -- a controversial figure who was twice ousted as state Supreme Court chief justice, first for refusing to remove a Ten Commandments monument and later for refusing to recognize the US Supreme Court's ruling legalizing same-sex marriage -- defeated Strange, who benefited from $10 million in advertising from the McConnell-aligned Senate Leadership Fund super PAC.

In Alabama, Bannon broke with Trump, who had gone to Huntsville for a campaign rally for Strange just days before the election.

But the two are still in frequent contact. Bannon spoke to Trump in recent days, the source said, arguing that from Trump's perspective the Senate is already lost because the President understands he has little support there.

As if to underscore that view, Tennessee Sen. Bob Corker -- the Senate foreign relations committee chairman who is retiring rather than running for re-election in 2018 -- accused Trump in a New York Times interview of putting the nation on a path to World War III and said Trump's presidency "would have to concern anyone who cares about our nation."

It was Corker who had urged Trump in a White House meeting to go to Alabama and campaign for Strange -- a decision the President came to regret -- according to a source who spoke to the President.

Bannon, meanwhile, has argued he is taking on Republicans who don't support Trump's policies.

Where's money coming from?

One source of financial support for Bannon-backed candidates is the Great America PAC, a super PAC led by former Ronald Reagan campaign manager Ed Rollins.

The group plans to roll out an initial set of three endorsements of Republican candidates this week.

It isn't expected to be as aggressive in seeking to unseat Republican incumbents as Bannon has been, but the super PAC does intend to support Senate candidates who back Trump's agenda and call for the elimination of the Senate's 60-vote threshold to break the filibuster -- potentially including Tennessee Rep. Marsha Blackburn, Ohio state treasurer Josh Mandel, Montana state auditor Matt Rosendale, West Virginia attorney general Patrick Morrisey and more.

It could also support candidates who could weaken Democratic senators seen as potential 2020 Trump opponents, including Elizabeth Warren in Massachusetts.

"The reality here is, you have to tap into that Trump agenda intensity. And those are the candidates who can win in the general election," said Eric Beach, the Great America PAC co-chair.

Bannon, meanwhile, is focused on damaging people who might be considering 2020 in both parties -- including Mitt Romney, who could run for the Senate in Utah if Hatch retires.

The key, the source familiar with Bannon's plans said, "is to prove the theory of the case" -- that Republicans who are anti-Trump should be gone.