Democratic pollster Mark Mellman said on Wednesday that Supreme Court Justice Brett Kavanaugh Brett Michael KavanaughHarris faces pivotal moment with Supreme Court battle Poll: 59 percent think president elected in November should name next Supreme Court justice Feinstein 'surprised and taken aback' by suggestion she's not up for Supreme Court fight MORE's confirmation hearings will wake up Republicans who were previously wavering on the party's leadership.

"There's no question that the Kavanaugh hearings woke up Republicans who [were] really not so sure about Donald Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE, not so sure how important it is for them to support Republicans in Congress, who they really don't like, I mean Republicans don't feel very favorably about their own congressional leadership," Mellman, CEO of the Mellman Group and a columnist for The Hill, told Hill.TV's Joe Concha on "What America's Thinking."

"Election is still a month off, and the reality is Kavanaugh is seated as justice of the Supreme Court. The issue's over. So are they going to go back to their previous lethargy or are they going to continue to be excited? We have no idea yet," he said.

A Politico–Morning Consult poll released on Wednesday found that 68 percent of Republicans said they were "very motivated" to vote in November's midterm elections.

Democrats are even more energized, with 77 percent saying they were "very motivated" to vote.

Marist Poll director Lee Miringoff said it is natural for both sides to become more energized as the midterms near.

"I'm not surprised that that might not have happened as we get closer anyways," Miringoff said.

"The president was planning to do what he's now doing, which is fairly independent of the whole Kavanaugh thing. So I would expect the Democrats to go in with the enthusiasm advantage," he continued.

— Julia Manchester