From time to time I've been catching up with a Republican strategist who is trying to help the GOP keep control of the House in this November's midterm elections. It's been an up-and-down ride.

"I would put the odds of keeping the House at exactly 50-50," he told me in January.

"I get how bad things seemingly are," he said during a particularly tumultuous time in April. "But if the election were today, I'd bet my son's college tuition we'd keep the House."

He was even more confident by June. "We keep the House," he told me. "I'd bet a lot of money on that."

And now: "The last 30 days have been really bad. I really wouldn't want to have the election today."

Looking back, each change in the strategist's mood has been the result of whatever President Trump was doing at that particular moment. His current anguish is the product of what he called "30 days of sh-t." By that, he meant the period of time beginning with Trump's decision to separate families crossing illegally into the United States and ending with his performance at the Helsinki summit.

Both hurt Republicans, the strategist said, but probably the Trump-Putin summit hurt more. When the president met with North Korea's Kim Jong Un, he said, many Republican-targeted voters saw a certain method in the madness. It actually helped GOP candidates. But when Trump met Vladimir Putin, those voters didn't see the method part.

[Related: Republicans worry about impact of Trump's Russia comments on midterm elections]

If the past is any lesson, memories will fade. But the problem going forward is that as future Trumpian incidents occur, Republicans will have less and less time to recover before Nov. 6.

"The next couple of weeks/months are critical in that we have had peaks and valleys before, but they always got fixed," the strategist said. "The fear is that we're running out of time and maybe they won't get fixed."

[A tale of two campaigns: Midterm elections 100 days out]

Perhaps the biggest underlying question of the coming elections is the relationship between presidential job approval and House GOP's re-election chances. It's often observed that Trump is keeping the favor of his base supporters. He is. But Republican strategists are watching his approval sink in some educated, affluent congressional districts with lots of independent voters the party needs to hold the House.

That undoubtedly hurts Republican candidates. "The Trump numbers, I don't know what to make of," said another GOP strategist working on the midterm elections. "It's not that his job approval ratings are good — they're not good — but we're not sure what role they play."

The second GOP strategist pointed to the economy, a subject of lots of undeniably good news. But whatever happy stories there are about growth and the stock market, he said, "It's still income and wages."

"With over half the country living paycheck-to-paycheck, the question for them is, is there enough improvement occurring that they can see themselves beginning to break out of that paycheck-to-paycheck cycle? If the answer is yes, that's a positive environment for Republicans. If the answer is no, then they [voters] are going to be willing to rock the boat again. I don't believe they have reached a conclusion yet."

Right now, the RealClearPolitics average of polls has Democrats up 7.3 percentage points in the so-called generic ballot question, which asks which party a voter plans to choose for his or her representative in Congress. That Democratic lead might be a little high; it could be skewed a bit by a recent Quinnipiac poll that found Democrats with a 12-point lead, which is four points higher than any other recent poll. But in any event, Democrats have long had the advantage this cycle; look at a graph of the polling average, and the blue line, on top, and the red line, on bottom, have never come close to meeting.

Many Republican strategists would feel comfortable about keeping the House if the Democratic poll lead were kept to four, or perhaps five, points. But it appears higher than that.

"Most of the data would lead a sober person to expect control of the House to be a 50-50 proposition, maybe a little worse for Republicans," said a third GOP strategist. "But most of the data at this time last election cycle led most of the pundits to celebrate President Hillary Clinton. I'm starting to think that this could be another instance where the group-think is wrong."

Maybe. But Republicans face a huge task. In a way, there has already been a wave in this election. It is the wave of 42 Republicans leaving the House. It's a record number, and there's no way to spin it as optimism for the future.

Still, all three strategists are keeping hope alive. Even the first strategist, rattled after those 30 bad days, sees the problems of the Democratic Party and remembers that Nancy Pelosi — just saying the name — is a great motivator for Republicans to get to the polls. Put that together with the Democrats who have embraced the unpopular issue of abolishing Immigration and Customs Enforcement, and that's a party a lot of voters do not want to embrace.

So GOP victory remains possible. What Republicans would like now is the absence of noise and distraction coming from the White House.

"We just need a decent level of calmness so we can message," said the first strategist. "If we could just have calmness, we could talk about the economy and ICE. And if we could talk about the economy and ICE, we'd be fine."

