President Trump and Senate Majority Leader Mitch McConnell held a remarkable press conference on Monday in the White House Rose Garden. After months of sniping at each other over the failure to repeal ObamaCare, and warnings from the president that he would target Senate Republican incumbents in upcoming primaries, the two leaders of the GOP implausibly insisted that they have a great working relationship. "We have the same agenda," McConnell told Trump in his opening statement. "We've been friends and acquaintances for a long time."

Trump was no less effusive in his praise for McConnell. "We are probably now, despite what we read," the president said, "at least as far as I'm concerned, closer than ever before. And," he added, "the relationship is very good."

Yeah, right.

Remember, it was just last week that Trump got into a war of personal attacks with Bob Corker, a key member of the Senate Republican caucus. Trump still hasn't backed down from his attacks on GOP Sen. Jeff Flake, whom he called "toxic," and who will face a serious primary challenge next year for his Arizona seat despite having voted for Trump's agenda all year. Trump also took aim this week at fellow Arizonan John McCain for his speech criticizing "spurious nationalism," a clear reference to Trump, warning that "at some point I fight back … and it won't be pretty."

Nor has Trump gone easier on McConnell himself. Trump demanded this summer that McConnell "get back to work" when Congress went on its traditional August recess. The president's Twitter feed is littered with attacks on McConnell for not ending the legislative filibuster, which has not actually impeded Trump's legislative agenda as much as McConnell's inability to get to 50 votes. At one point, McConnell slapped back at Trump for his inexperience in governing, and the White House slapped right back at McConnell for not "doing his job."

For months, the relationship's toxicity has been public enough to be beyond dispute. So why did Trump and McConnell put on a show of camaraderie on Monday? Simple: They need each other too much. If they are going to stave off a civil war in advance of the midterms — a civil war being fomented by Trump's former adviser Stephen Bannon — they simply must work together to get things done. That means at least pretending that they like each other.

Since leaving the White House, "Bannon has dedicated himself to attacking McConnell and other members of the GOP establishment," The Washington Post reported after the Rose Garden presser. Bannon blames the lack of progress on the populist-nationalist agenda on a lack of support from Republicans in Congress, and has pledged to launch primary challenges to get Trump-supporting candidates in place — or at least to boot insufficiently loyal Republicans, even if it gives Democrats openings to win control of Congress. Until Monday, Trump appeared to share that ambition.

However, it seems that both McConnell and Trump have come around on the conclusion that they need wins now, not later, and the biggest agenda item — tax reform and the budget — will take as much Republican unity as they can get. Trump's economic agenda relies on significant changes to the tax code, hoping to boost the economy high enough in the short run to get more political room to maneuver ahead of the midterms. At the moment, they have built more support for those efforts than McConnell managed with the ObamaCare repeal. Both Susan Collins and Lisa Murkowski announced that they would likely support the combined effort under reconciliation as it is currently proposed, and Rand Paul has signaled that he's a probable yes, too.

Those three sunk ObamaCare repeal more than once. Getting the senators from Maine and Alaska — and hopefully Kentucky — onboard gives McConnell some breathing room — but he still needs Corker, McCain, and Flake to stay within the caucus. That leaves McConnell and Trump perilously close to failure on yet another bill. Both will take heat from constituents if they can't get Trump's economic agenda off the launch pad.

For now, Trump's economic agenda eclipses his disruptor agenda, which left Bannon and his project out in the cold on Monday … for now, anyway. If the tax package and budget passes under reconciliation, it may take some of the steam out of the "war on the Republican establishment, reminding voters of McConnell's observation on Monday. "You have to nominate people who can actually win," he told the press in reference to Bannon's effort, "because winners make policy and losers go home."

That's true. But when winners don't make policy either, then there isn't much point to winning. If McConnell and Trump can't get tax reform and the budget passed on Republican terms, then their phony bromance will have all been for nought.