Senator Mitch McConnell and President Donald Trump Yuri Gripas | AFP | Getty Images

Senate Majority Leader Mitch McConnell had a warning for his colleagues: You may have to work between Christmas and the New Year to accomplish all of our goals. Those targets include spending measures to avoid a partial government shutdown. The Kentucky Republican's to-do list also contains clear nods to President Donald Trump's priorities. "We need to confirm more of the president's nominees for the judiciary and for the executive branch," McConnell said Tuesday. He also surprised some by announcing that "at the request of the president and following improvements to the legislation," the Senate would take up bipartisan criminal justice reform this month. Shortly after McConnell's remarks, Trump met with Senate Minority Leader Chuck Schumer and House Minority Leader Nancy Pelosi, the likely next House speaker when Democrats take a majority in three weeks. Unlike McConnell, they showed no desire to help Trump as he seeks money for his proposed border wall in a year-end spending bill. Schumer and Pelosi flatly denied Trump's request for funding in a heated on-camera discussion that ended with the president saying he would be "proud" to shut down the government over the border barrier. In the nearly two years since Trump took office, the president and McConnell have forged an at times uneasy partnership as they sought joint goals such as reshaping the federal courts and overhauling the U.S. tax code. As Tuesday's events showed, the prospects for tension and stalemate over the next two years of divided government make the president's relationship with McConnell all the more important for Trump's policy goals — and potential political survival. Democrats picked up 40 House seats in November's midterm elections, and will have at least 235 members in their House majority next month. The gains make it impossible for Trump to push any of his goals — on health care, immigration or taxes — through the House without Democratic support. But in the Senate, where the GOP will hold 53 of 100 seats next year, the president can still get a lot done, with an assist from McConnell.

McConnell has confirmed Trump's young, conservative judicial nominees at a blistering pace as both men try to alter the path of U.S. courts for years to come. The Senate is the only chamber that controls confirmations. McConnell and Senate Republicans could also provide a final barrier for the president if House Democrats pursue Trump's impeachment when special counsel Robert Mueller's Russia investigation ends. Democratic leaders have shown no interest in impeachment yet, but that could change depending on revelations in the coming months. Though the brash Trump and often-understated McConnell outwardly have little in common, their sustained working relationship will be critical for the president in the nearly two years before Trump's re-election bid. McConnell's office declined to comment on the president and senator's relationship, while the White House did not respond to a request to comment.

Trump and McConnell's up-and-down allegiance

Trump and McConnell have enjoyed major victories together. They secured the hard-fought confirmations of Supreme Court Justices Neil Gorsuch and Brett Kavanaugh. They navigated a closely divided Senate to cut taxes for businesses and many individuals, a long-held GOP goal. But the president has had his moments of frustration with McConnell. He publicly swiped at the Senate Republican leader several times last year after the chamber failed in its attempts to repeal the Affordable Care Act. In August 2017, McConnell said Trump had "excessive expectations" about how quickly the legislative process moves. Trump shot back in one of a string of tweets criticizing the senator: "Senator Mitch McConnell said I had 'excessive expectations,' but I don't think so. After 7 years of hearing Repeal & Replace, why not done?" Trump tweet The leaders have since projected a better working relationship. In October 2017, they held a news conference to show a united front as they tried to push tax reform through Congress. Trump said the two were "closer than ever before" and had a "very good" relationship. McConnell stressed that "we are together totally on this agenda to move America forward." Both touted an area of progress that they will likely play up frequently in the coming months of divided government: judges. Trump called judicial confirmations "an untold story" of success that "has consequences 40 years out." Even before Kavanaugh's confirmation, McConnell called Gorsuch's appointment "the single most significant thing this president has done to change America." The Senate GOP leader successfully blocked Judge Merrick Garland, President Barack Obama's 2016 appointment to fill the late Justice Antonin Scalia's seat. McConnell also pointed to "a lot of vacancies at both the circuit court and district court level" — which he also helped to create by stifling Obama's nominations. The Senate has confirmed 84 judges in the current Congress. The growing tally of judicial confirmations, helped along by McConnell's own desire to shape the federal courts, is something Trump will likely highlight if he finds legislative victories harder to achieve next year. Trump will face pressure on multiple fronts when Democrats take control of the House. The party has already promised to pursue his tax returns and investigate his immigration policy and possible misuse of taxpayer money by Cabinet officials, among other issues. Democrats will push back on many of the president's legislative priorities. Pelosi and Schumer seem more than happy to try to bait the president into a public outburst, as they did on Tuesday.