Mitch McConnell paused as he searched for the words to sum up the early days of 2019.

“So, I would say this is a little bit of a, uh, challenging beginning to the new year,” the Kentucky Republican said Tuesday at his weekly news conference with a slight smile. “But we will work our way through it.”

McConnell was speaking specifically of business in the Senate, the chamber he oversees as majority leader. But his words could have just as well been about himself.

It’s been a bumpy couple of weeks for the longtime lawmaker, who has cultivated a reputation for being a savvy political strategist, deft dealmaker and Senate institutionalist.

The longest government shutdown in history has no end in sight. It is gumming up other Senate priorities and has put McConnell in an unfamiliar role — spectator.

By choice, he has stepped away from the talks to resolve the impasse over $5.7 billion for President Trump’s border wall, which is at the core of the dispute, while refusing to vote on House bills to reopen the government. Trump wants wall funding. Democrats don’t. McConnell is leaving it to them to work it out.

Still, he has retained the support of most fellow Republican senators, who appear to be largely united behind his strategy, despite some growing concerns about the impact of the lapse in government services.

One after another, McConnell’s top lieutenants took turns speaking after him Tuesday, blaming Democrats for the shutdown and standing in lockstep with the majority leader.

As the longest shutdown in history continues, President Trump's options for reopening the government are becoming limited. Here are a few paths he could take. (Monica Akhtar/The Washington Post)

“The corpus, the main group of the caucus, will stay with the leader,” Sen. Richard C. Shelby ­(R-Ala.), chairman of the Senate Appropriations Committee, said to reporters separately. “And the leader right now is hanging with the president.”

But where exactly McConnell is leading them remains unclear. He has effectively ceded the talks to a mercurial Republican president determined to fulfill a campaign promise and Democratic leaders under pressure from their base to stop him.

Asked whether McConnell knows where the president stands, Shelby replied, “You’ll have to go up there and ask him.”

McConnell’s posture could have far-reaching implications in his own bid for reelection in 2020, other key Senate races that year, and his influence in the new era of divided government.

When it comes to the shutdown, McConnell’s position is simple: It’s on Trump, Senate Minority Leader Charles E. Schumer (D-N.Y.) and House Speaker Nancy Pelosi (D-Calif.) to strike a deal to end the standoff.

“The solution to the problem is for the president of the United States, the only person of the 330 million or so of us who can sign something into law, reaches an agreement with the Democratic majority in the House and enough Democrats in the Senate,” McConnell said.

His allies say he can hardly be blamed.

McConnell spearheaded a vote that passed unanimously in December to pass a stopgap bill to avert a shutdown, only to get burned as Trump abruptly declared that he would not support it.

“The only thing that’s going to pass is something Senate Democrats and the president agree on,” Sen. Marco Rubio (R-Fla.) said. “Nothing McConnell can do to force Senate Democrats to do something.”

For their part, Senate Democrats are calling on McConnell to hold a vote on a bill to reopen the government to put more pressure on Trump to agree to end the standoff.

“There is only one person who can help America break through this gridlock: Leader Mitch McConnell,” Schumer said Tuesday. “For the past month, Leader McConnell has been content to hide behind the president, essentially giving him a veto over what comes to the floor of the Senate.”

In the past, McConnell has been a central player in sensitive negotiations. During the Obama presidency, he found an effective negotiator in then-Vice President Joe Biden.

But this stalemate has distinct political implications. Getting on the wrong side of Trump on immigration — an issue that animates the conservative base — could invite dangerous hostility to Republicans facing reelection.

“If Republican members abandon Trump on this issue, it could have real primary consequences for them in 2020, and so everyone is staying the course,” GOP pollster Chris Wilson said.

After padding their majority to 53 to 47 on a friendly map in last year’s elections, Republican face a more difficult situation in 2020. They are defending 22 seats, while the Democrats defend 12.

Among the senators facing reelection is McConnell, who is running for a seventh term in a conservative state where Trump is popular. The last time McConnell was on the ballot, he faced a primary challenger — Matt Bevin, who is now Kentucky’s governor.

While the threat of opponents running to the right of any incumbents who break from Trump looms in many states, the shutdown also presents a potential general election challenge for Republicans running in states Trump lost.

Sens. Cory Gardner (R-Colo.) and Susan Collins (R-Maine), both up for reelection in states where Hillary Clinton won in 2016, have been outspoken in their concerns about the impact of the shutdown.

While shutdowns were not focal points in recent elections, Republicans have expressed worry that the longer this one drags on, the more potential political damage they expose themselves to in the long run.

The impact on federal workers, farmers and others has raised some alarm in the party. Democrats are reminding voters of Trump’s promise to make Mexico pay for the wall, which he has not fulfilled. With no obvious resolution in sight, nervousness is growing about how it will end.

Given McConnell’s limited participation, the answer to that question is largely up to Trump, who has proved to be unpredictable.

“I think right now, the Republican senators are . . . not as much a part of this discussion, obviously, because of the need for the president and the Democrats to come together,” said Sen. John Thune (R-S.D.), McConnell’s top deputy.

McConnell was absent from a pair of recent news conferences that included other Republican congressional leaders. In one instance, an aide said he did not know Trump was planning to hold one.

McConnell’s relationship with Trump has been something of a roller coaster.

It reached a low point after the collapse of the Republican push to repeal and replace the Affordable Care Act. But it improved after the passage of the sweeping GOP tax law.

McConnell’s refuge during the turbulent Trump era has been inside the Senate, where he has taken pride in shepherding judicial nominees through at a record clip and passing the tax bill.

In response to the shutdown, Senate Democrats have blocked some of McConnell’s other priorities from moving forward — a maneuver that has bothered the majority leader.

“Clearly, the Democrats’ priorities are way out of whack here,” McConnell said. “Way out of whack.”