Senate Republicans were defiant Sunday, one day after Brett M. Kavanaugh was sworn in as the 114th Supreme Court justice, brushing aside concerns about how they handled the brutal confirmation process and the potential costs in next month’s midterm elections.

But Republicans also faced sharp questions about the fallout in a fast-changing country that has seen the #MeToo movement gain prominence and Democratic voters electrified in opposition to President Trump and to Kavanaugh.

Senate Majority Leader Mitch McConnell (R-Ky.) suggested that the GOP’s base voters could reward the party with strong turnout for standing by Kavanaugh in the face of sexual assault allegations that prompted protests and outrage from both sides of the political aisle.

“We stood up to the mob,” McConnell said on “Fox News Sunday.” “We established that the presumption of innocence is still important. I’m proud of my colleagues.”

His charged language was shared by other Republicans, who referred to Saturday’s near-party-line vote of 50 to 48 as a galvanizing and polarizing moment.

“I’ve never been more pissed in my life,” Sen. Lindsey O. Graham (R-S.C.), a Trump ally, said on “Fox News Sunday.” “I’ve never campaigned against a colleague in my life. That’s about to change.”

Senate Democrats, disappointed by Kavanaugh’s ascension, argued that many voters nationally — women, in particular — remain infuriated by the GOP’s treatment of Christine Blasey Ford, who detailed in emotional testimony her allegations that Kavanaugh sexually assaulted her when they were teenagers. Kavanaugh has denied the allegations.

Sen. Mazie Hirono (D-Hawaii), who gained national notice during the confirmation fight for urging men to “shut up and step up” in the wake of Ford’s allegations, said Democratic voters would be highly motivated to turn out and punish Republicans for the limited FBI investigation of Kavanaugh following his hearing.

“He’s going to be on the Supreme Court with a huge taint and a big asterisk after his name,” Hirono said on ABC News’s “This Week.” “Everyone knows when you just interview a small number of people and not the dozens of others who wanted to be interviewed by the FBI, it’s a sham.”

Rep. Jerrold Nadler (D-N.Y.) — who would chair the House Judiciary Committee should Democrats win the House majority next month — has said he plans to launch an investigation of Kavanaugh if Democrats win power.

“Jerry Nadler will do what Jerry Nadler will do,” Hirono said, adding that she would not rule out an effort in the coming months to impeach the high court’s newest justice.

Other Democrats, however, took a different approach to the impeachment question, mere weeks ahead of the elections in which they are eager to rally their core voters and connect with moderates and independents.

Sen. Christopher A. Coons (D-Del.) was cautious when asked about the prospect of Democrats moving to impeach Kavanaugh should they win the House majority.

“I think that’s premature,” Coons said on NBC News’s “Meet the Press.” “I think talking about it at this point isn’t necessarily healing us and moving us forward.”

Coons, instead, turned his attention to Trump for mocking Ford last week and said the Kavanaugh controversy was an indictment of the president’s character as much as it was a battle within the Senate, coming as more women are speaking up about harrowing experiences.

“One of the biggest tragedies of this past week was to watch the president of the United States publicly mocking and ridiculing Dr. Ford,” the senator said, calling it a “low mark in his presidency.”

Last week in Mississippi, Trump attacked Ford’s story at length — drawing laughs from the crowd.

“ ‘I don’t know. I don’t know.’ ‘Upstairs? Downstairs? Where was it?’ ‘I don’t know. But I had one beer. That’s the only thing I remember,’ ” Trump said of Ford as he mocked her onstage.

Sen. Susan Collins (R-Maine) — whose vote was decisive — appeared on CBS News’s “Face the Nation” and was far more measured as she stood by her decision to support Kavanaugh.

“I am convinced that Dr. Ford believes what she told us and that she was the victim, a survivor, of sexual assault and that that has been a trauma that has stayed with her for her entire life,” Collins said.

But, she said, “I could not conclude that Brett Kavanaugh was her assailant.”

When pressed by moderator John Dickerson about whether her view on Ford may be viewed by her critics as skepticism generally of women who have shared similar stories, Collins defended her position and said she was evaluating a specific case.

“When I hear that, it causes me huge pain because I have met with so many survivors of sexual attacks, including close friends. And these women have the right to be heard,” she said.

Collins, who will face reelection in 2020, said she was not alarmed by Democrats’ calls for her to be challenged following her vote for Kavanaugh, with some urging Susan E. Rice, who was the ambassador to the United Nations under President Barack Obama, to run.

“Her family has a home in Maine, but she doesn’t live in the state of Maine,” Collins said on CNN’s “State of the Union.”

The political scramble extended to Senate Democrats, with those of them running in states won by Trump in 2016 explaining a critical vote that could, in part, determine their fate.

One of them was Sen. Heidi Heitkamp (N.D.), who told CBS’s “60 Minutes” that her opposition to Kavanaugh was based not only on Ford’s testimony but also on her disappointment with Kavanaugh’s combative testimony and her lingering questions about his answers.

“What I would say is — even if you don’t believe or believe Dr. Ford, the other issue is one of temperament, one of impartiality and blind justice,” Heitkamp said. “And I think that adds to the case being made that a ‘no’ vote is the appropriate vote.”

Heitkamp added, “I think that the politically expedient vote here was a ‘yes’ vote . . . [but] this isn’t about politics.”

Seung Min Kim and Josh Dawsey contributed to this report.