Judge Brett Kavanaugh's promotion to the U.S. Supreme Court is now all but assured. What's less certain is whether conservative voter motivation, wrought by outrage over Democratic efforts to stop his nomination, was just a short-term "sugar high" for Republicans, warns analyst Charlie Sykes.

Polls indicate the party is seeing an uptick in voter enthusiasm. But it will have to last another month to help the party in the midterms, said Sykes, a prominent conservative commentator.

"I have a gut sense that whichever side loses this weekend [when Kavanagh is expected to be confirmed], that anger is the rocket fuel of voter motivation," he said.

"Sometimes in politics, you can lose by winning."

He cited the passage of President Obama's Affordable Care Act, one of the greatest legislative victories of recent history for the Democrats, but which resulted in dramatic defeats for the party in the 2010 midterms.

The current president's son, Donald Trump, Jr., seemed to recognize how partisan anger can energize Republicans, tweeting warnings that — despite Kavanaugh's Supreme Court seat appearing to be locked up — "the fight isn't over."

"This is war. Time to fight. Vote on Nov 6 to protect the Supreme Court!" he tweeted.

Trump supporters - The fight isn’t over. You better believe that Democrats are going to do everything in their power to impeach Kavanuagh from the Supreme Court if they take control of Congress in November. <br><br>This is war. Time to fight. Vote on Nov 6 to protect the Supreme Court! —@DonaldJTrumpJr

Amid conservative anger over the Kavanaugh controversy, an NPR/PBS/Marist poll last week showed a wide Democratic edge in motivation that dwindled dramatically — from a 10-point lead to two points, the margin of error.

Conservatives were appalled that Kavanaugh's promotion could be put in peril by uncorroborated allegations of sexual misconduct by a handful of women. His accusers included research psychologist Christine Blasey Ford, whose Senate testimony was widely viewed as credible, and who alleged that Kavanaugh tried to rape her at a house party in 1982. An FBI investigation into the allegations, which did not include interviewing Ford, turned up "no corroboration," according to a Republican executive summary.

'A fairness issue'

To an extent, Sykes said, "this issue has united the right in a way we have not seen in the Trump era."

While political momentum may have been on the Republican side, sustaining that jacked-up anger over Kavanaugh may be key to the party's hopes of holding onto the Senate.

In a frenzied Trump-focused news cycle and with a public with a short memory, though, there's an "expiration date" on even the biggest news stories, Sykes said. It wasn't so long ago, for example, that the talk of Washington was an anonymous op-ed in the New York Times from a senior administration official blasting Trump's presidency.

Even so, it shouldn't be overstated how important a conservative-dominated Supreme Court is to Republicans. To understand why they would be so fired up, consider that the court's composition has been a key motivator for Republicans for years, with voters citing it as a major reason they were willing to overlook many of President Donald Trump's flaws in the 2016 election.

"You had conservatives who are skeptical of Trump, but ultimately decided if they got a Supreme Court justice out of his presidency, it would be worthwhile, that particular tradeoff," Sykes said.

Identity politics plays into the current Republican anger, too, with conservative women pushing back against being labelled as anti-feminist for backing Kavanaugh.

Kavanaugh testifies to the Senate judiciary committee during his Supreme Court confirmation hearing on Sept. 27 in Washington, D.C. (Win McNamee/Getty Images)

"Conservative women are fired up because they're tired of this false binary — this narrative that you either believe this, you stand by it, or you're a monster," said Ellie Krasne, a 33-year-old Republican voter in Washington, D.C.

Patrice Onwuka, a senior policy analyst with the conservative nonprofit Independent Women's Forum in Washington, said conservatives see the Kavanaugh battle "as a fairness issue."

"We're in the last stretch...We need to make sure these key Senators hear from us." <a href="https://twitter.com/PatricePinkFile?ref_src=twsrc%5Etfw">@PatricePinkFile</a> <a href="https://twitter.com/IWV?ref_src=twsrc%5Etfw">@IWV</a><br><br>Contact these Senators NOW! Vote YES.<br>Collins 202-224-2523 <a href="https://twitter.com/SenatorCollins?ref_src=twsrc%5Etfw">@SenatorCollins</a> <br>Flake 202-224-4521 <a href="https://twitter.com/JeffFlake?ref_src=twsrc%5Etfw">@JeffFlake</a> <br>Murkowski 202-224-6665 <a href="https://twitter.com/lisamurkowski?ref_src=twsrc%5Etfw">@lisamurkowski</a> <a href="https://twitter.com/hashtag/ConfirmKavanaugh?src=hash&ref_src=twsrc%5Etfw">#ConfirmKavanaugh</a>⚖️ <a href="https://t.co/hZR7cn29DS">pic.twitter.com/hZR7cn29DS</a> —@IWV

"We certainly recognize allegations of sexual assault are serious, but we also believe in fairness and due process, which is at risk."

"We're getting an infusion of energy from people saying what was done to Judge Kavanaugh was wrong, and we don't want to see a bedrock principle — the presumption of innocence — lost in this case."

'Fixated on not liking Trump'

"Never Trump" conservative Mac Stipanovich, a veteran Republican strategist and Florida activist who admits to "loathing" the U.S. president, recalls a time not long ago when the enemy of his enemy, the Democrats, had almost become his friend.

"I had become so fixated on not liking Trump. On loathing Donald Trump with a passion. On opposing almost everything he wanted to accomplish," Stipanovich conceded. "Until now."

Activists hold march and rally in opposition to Kavanaugh in Washington, D.C. (Kevin Lamarque/Reuters)

Stipanovich was ambivalent about judge Kavanaugh's nomination. But after what he perceived to be Democratic antics and a co-ordinated character assassination of the nominee, he was so incensed that he ditched plans "to deliver a blow to Trumpism" by voting a straight Democratic ticket in November.

He didn't expect that degree of anger to override his contempt for the president.

At the same time, Stipanovich says if Kavanaugh does prevail, it gives Democrats "the rage edge."

He doesn't discount the idea that Trump was aware of polls indicating a boost in Republican voter interest last week, when the president changed course from his measured defence of Ford as "credible" to openly mocking her on stage at a political rally.

"He may have seen something in the polling. But it was obviously an about-face. And arguably, it was not very helpful," Stipanovich said.

There are still 30 days until the Nov. 6 midterms, he noted, and Democrats won't soon forget Kavanaugh's confirmation, even if Republicans eventually cool their heads over the whole episode.

Ellie Krasne, 33, a Republican voter in Washington, D.C., says conservative women are angry about being falsely labelled as anti-feminist for supporting Kavanaugh. (Submitted by Ellie Krasne)

"If this was happening five days from election day, it might be a very different moment," Stipanovich said.

Whereas election cycles before Trump once braced for potential "October surprises" — late-arriving news events that dropped a month before election day to affect the outcome — Stipanovich doubts that passions over Kavanaugh's nomination battle will be the only potential election game changer this month.

"That's hard to imagine. We have at least weekly surprises now; almost daily surprises," he said. "Trump so controls the news cycles and the narratives that he makes them like popcorn."