President Trump congratulates chief strategist Stephen K. Bannon during the swearing-in of senior staff in the East Room of the White House in January. (MANDEL NGAN/AFP/Getty Images)

In the two months since Stephen K. Bannon was shunted from the White House and returned to the helm of Breitbart News, the former chief strategist has declared “a season of war” on establishment Republicans and even worked to help a Senate candidate opposed by President Trump.

Yet Bannon and Trump are anything but estranged. Instead, they have remained in frequent contact, chatting as often as several times a week, according to multiple associates of both of them.

Trump usually initiates the talks because incoming calls now are routed through chief of staff John F. Kelly and his disciplinarians. The conversations are dictated by the whims of the president, who dials his former chief strategist when something he reads, watches or hears piques his interest.

When Trump phones, Bannon answers with a deferential “sir,” a nod to respect from a man who shuns hierarchies. They chew over politics, float ideas and catch up on gossip. They also each ask after the other to shared confidants and friends, not unlike teenagers checking to make sure the other is not upset or disapproving.

In one of his many private chats with Fox News personality Sean Hannity, Trump recently asked, “Is Steve still with me?” according to two people familiar with the conversation.

Bannon’s bond with Trump — forged in their shared nativist instincts, us-against-them mindsets and disruptive impulses — by all accounts remains strong, even as their political agendas show signs of diverging heading into the 2018 midterm elections.

Trump and Bannon’s evolving partnership — described by nine aides, friends and confidants, many of whom insisted on anonymity to offer a more candid portrait — is nuanced, combining tension with affection and, for now at least, is mutually beneficial.

White House senior adviser Jared Kushner, left, senior policy adviser Stephen Miller, and chief strategist Stephen K. Bannon watch as President Trump speaks in the Oval Office of the White House on April 20. (Jabin Botsford/The Washington Post)

Bannon tells confidants he sees himself as “the president’s wingman,” tending to his base and taking on his enemies. Trump still frequently consults him, and Bannon believes he is executing the president’s wishes.

“It’s better for Bannon because he doesn’t have to waste time jockeying for position in a nepotistic White House,” conservative commentator Ann Coulter wrote in an email. “And it’s better for Trump precisely because Bannon doesn’t have to tiptoe around Trump’s ‘first among equals’ relatives, but can use Breitbart to forcefully remind Trump of the issues he ran on.”

But the president is free to distance himself publicly from Bannon whenever things get uncomfortable — such as at a news conference this Monday with Senate Majority Leader Mitch McConnell (R-Ky.), where Trump said he may ask Bannon not to take on some Republican Senate incumbents.

With McConnell looking on, Trump told reporters, “I like Steve a lot. Steve is doing what Steve thinks is the right thing. Some of the people that he may be looking at, I’m going to see if we talk him out of that, because, frankly, they’re great people.”

Strategist Ed Rollins, chairman of Great America PAC, a pro-Trump group, said, “The president can say, ‘Well, that’s Bannon being Bannon,’ as opposed to, ‘That’s my chief strategist down the hall from me.’ The president has a responsibility of running the government. Bannon is free to throw rocks against the windows, which is sometimes more fun.”

The danger for Trump is that Bannon is acting less as a loyal steward of the president’s personal brand and more as a political opportunist, appropriating the Trump movement to advance a broader ideological agenda — not always aligned with the president’s governing goals — and to permanently reshape American politics.

There are tensions already. Bannon is agitating some of the very senators Trump is trying to persuade to support his tax cuts plan, which would finally hand the president a signature piece of legislation.

This past week, Trump privately offered his support to three establishment Republicans up for reelection next year — Sens. John Barrasso of Wyoming, Deb Fischer of Nebraska and Roger Wicker of Mississippi — even though Bannon and his allies have been considering backing primary challengers to the incumbents. Trump's calls to these senators were first reported by Politico.

This was a coup for McConnell, who has been plain about his strategy for the midterms. Standing beside Trump at Monday’s news conference, McConnell said, “You have to nominate people who can actually win, because winners make policy and losers go home.”

Former chief White House strategist Stephen K. Bannon takes part in an interview with Fox News Channel host Sean Hannity on Oct 9. (Craig Ruttle/Associated Press)

In other ways, however, Trump and Bannon are aligned. After Bannon made a rare television appearance on Hannity's Oct. 9 show to bludgeon Senate Foreign Relations Committee Chairman Bob Corker (R-Tenn.) and to declare war on McConnell and the Republican Party, Trump called his former aide to praise his performance, according to two people familiar with the exchange, which was first reported by the Wall Street Journal.

“Donald Trump seems to like the mischievous aspect of this a bit,” said Bill Whalen, a fellow at Stanford University’s Hoover Institution. “If there’s any motto of this administration, it’s thriving on chaos and throwing curveballs, and so I have to think there’s some aspect of primarying Republicans that appeals to Donald Trump’s disruptive nature.”

Trump called Bannon this month after an unflattering Vanity Fair report about the "unraveling" presidency. The piece claimed, among other things, that Bannon had told friends he estimated Trump only had a 30 percent chance of making it through his full first term. Bannon denied making the comment — the media coverage of which had upset and unnerved Trump — and the president told aides he believed Bannon's denial.

Privately, Trump voices frustration with the public perception that Bannon feeds him big ideas and dictates his policies, as if the president were the strategist’s puppet. Rather, Trump thinks of Bannon as his gut check, in the words of one top aide. When Bannon was still at the White House, Trump admired that he would frequently remind him what he had promised on the campaign trail or spar with more traditional-minded advisers in front him, according to West Wing staffers.

Since leaving the White House in mid-August, almost exactly one year after he joined Trump’s campaign, Bannon has appeared re-energized.

Frequently disheveled and unshaven, and mocked for his mostly black, multi-layer wardrobe, Bannon has been taking better care of himself. He has lost nearly 15 pounds by loosely adhering to what his associates affectionately call “a hippie diet.” He swigs kombucha and cider vinegar shots, and favors green smoothies.

Friends say Bannon is invigorated with a singular focus. He is trying to build the equivalent of his own political party, one that aims to explode the Republican establishment and what he and his allies dismiss as the “McConnell industrial complex,” all while shrouding it in the cloak of advancing Trump’s agenda.

In a provocative speech last weekend to the Values Voter Summit, Bannon declared "a season of war against the GOP establishment."

“Up on Capitol Hill, it’s the Ides of March,” Bannon said, referring to Shakespeare’s “Julius Caesar,” the story of a Roman leader assassinated by a group of rebellious senators who conspired to stab him in the back. Threatening McConnell, Bannon continued, “They’re just looking to find out who is going to be Brutus to your Julius Caesar.”

Bannon has been crisscrossing the country, meeting with donors and recruiting primary challengers to Republican senators. Bannon’s personal litmus test is multifold: His candidates must take a hard line on both immigration and trade — signature issues for Trump — as well as pledge to vote to overturn the filibuster rule in the Senate, which would enable more legislation to pass with just a 51-member majority, and to oust McConnell from leadership.

It is unclear whether Bannon will be able to recruit credible candidates in all of the races he is targeting, or whether he will be able to steer enough money to their campaigns for them to win.

"Success might not come so easily," GOP strategist Karl Rove, the architect of George W. Bush's presidential campaigns, warned Bannon in a Wall Street Journal column Wednesday. Rove noted that Bannon's machine was revved up last year behind a conservative primary challenger to House Speaker Paul D. Ryan (R), but the speaker won his Wisconsin district with 84 percent of the vote.

The Alabama Senate primary last month posed the biggest stressor to date for Trump and Bannon’s post-White House relationship. Bannon went all in for Roy Moore, a polarizing former judge and evangelical whose rhetoric and policy positions are considered by many to be racist and homophobic, while Trump supported Sen. Luther Strange, who had been tapped to fill a vacant seat and was favored by McConnell.

In the closing days of the race, Trump and Bannon staged dueling rallies in the state — associates described them as “friendly adversaries” — but despite broad enthusiasm for the president among Alabama Republicans, Moore won.

Former chief White House strategist Stephen K. Bannon speaks at a rally for Senate candidate Roy Moore on Sept. 25 in Fairhope, Ala. (Brynn Anderson/Associated Press)

The outcome rattled Trump, who for the first time watched as his base bucked him. But he did not fault Bannon. Instead, aides said, he blamed his own advisers for pushing him to be involved in a race he had always felt skeptical about.

After appearing with Strange at their rally, according to two people familiar with the exchange, Trump privately leveled one of his most damning criticisms: The senator, he worried, lacked energy. He was, as the president phrased it, “low-key.”

Last Monday, Bannon was on a conference call, strategizing how to upend the 2018 midterms, when Trump stepped into the Rose Garden for his unannounced news conference with McConnell.

Bannon told associates in that moment that he believed Trump was a performance artist and McConnell was his hostage bride in a marriage of convenience — in this case, to pass sweeping tax cuts. In his heart, Bannon said, the president is still a revolutionary and is counting on him to help lead the charge against the gates.

At one point during the call, Bannon watched as the president declared himself and McConnell “closer than ever before.”

That’s when Bannon let out a hearty belly laugh.