– President Donald Trump is caught in an unrelenting swirl of scandal, and President Barack Obama's signature health care law is still intact. Democratic energy is unbridled, and Republican enthusiasm is uncertain.

Republicans enter the homestretch of the 2018 campaign season gripped by a long list of anxieties as they attempt to maintain their majorities in both chambers of Congress, a mission that, to some top strategists, looks increasingly daunting.

But their biggest fear, according to conversations with a dozen GOP strategists and pollsters, is that Republicans won't be able match the motivation of an expanding Democratic base that is enraged and emboldened by Trump's presidency.

"Midterms are about anger management and failed expectations," said veteran North Carolina-based GOP strategist Paul Shumaker. "That's applicable to either side, depending on who is in the White House. This time, it's applicable to Republicans."

Certainly, the vast majority of Republicans approve of Trump, and many are pleased with his Supreme Court nominees and the passage, by the GOP-held Congress, of a major tax overhaul.

Even in congressional districts where Trump is unpopular, many Republican strategists are hoping that voters will draw distinctions between their individual members of Congress and the president, as they did in 2016, and will reward the incumbent GOP for a strong economy. Republicans still largely feel bullish about the Senate, where the red state-heavy map favors them, and where Democrats are having their own challenges.

Yet with Election Day less than eight weeks away, there is no doubt that Republican operatives are nervous about their November fortunes, especially when it comes to defending the House.

The Trump factor

Republicans concede that it has been a rough summer for their party — and the president has often been at the center of the GOP's most challenging moments over the past few months.

There was the Trump administration's short-lived but deeply controversial policy of separating children from their parents at the border; a widely panned appearance with Russian President Vladimir Putin in which Trump refused to hold him accountable for Moscow's interference in the 2016 election; the guilty plea of his longtime lawyer Michael Cohen to, among other things, campaign finance violations; and the guilty verdict for his former campaign chairman, Paul Manafort, in a financial fraud trial. And then there are the tweets that constantly knock Republican lawmakers off their carefully planned policy messages.

Taken together, it has created an environment that Republican strategists say makes it even harder for independents to swing their way, adding to the traditional challenges facing the president's party in the first midterm of a new White House.

"All it's doing is adding more straws on the camel's back," said longtime GOP pollster Glen Bolger. "Nothing's broken, but it's not good, it's not helping."

Even as Trump's approval rating remains sky-high among Republican voters, with the general public that number has largely been mired in the low 40s or worse. Strategists fear that it could drop more.

"Even if a suburban candidate is on message, there's no oxygen, nobody's paying attention because President Trump is such a dominant player, he's the one getting all the attention, particularly for people who watch cable," said Henry Barbour, the Republican National Committee member from Mississippi, calling Trump a "key driver," adding, "whether you love him or hate him."