With four days to go before the United States midterm elections, Democrats are leading national polls as both parties make their final push for votes.

Meanwhile, President Donald Trump has reversed his decision to cancel campaign rallies in Kansas and Iowa, while a legal dispute threatens to delay the Senate result in Alaska.

Here’s what you need to know.

What do the latest polls say?

Democrats lead Republicans by 51.4 percent to 43.2 percent, according to RealClearPolling, with a difference of 8.2 percentage points.

Charles Franklin, professor of law and public policy and director of the Marquette Law School Poll, said Trump’s declining approval ratings and economic concerns are alarming Republicans.

A Marquette Law School poll conducted in Wisconsin from October 14 to 22 found that 37 percent approved of Trump’s performance, while 61 percent disapproved.

The poll also found that only 16 percent of respondents felt better off financially than a year ago, compared with 42 percent who said they were worse off. Another 42 percent said their situation had not changed.

“Democrats are more enthusiastic and more certain they will vote,” Franklin told Global News Insight.

“That is giving Democrats an important edge, and reflects Republican disappointment in current national conditions.”

In Arizona, where voters face rising living costs, a retiree told Global News Insight that grocery prices had become a major concern.

“We’re retired, and every time we go to the grocery store, it makes me wonder what the heck is going on,” the voter said.

In Texas, Democrat James Talarico leads Republican Ken Paxton by 49 percent to 43 percent, according to a CNN poll released on Thursday. In Michigan, the same pollster suggested Democrat Abdul El-Sayed was ahead of Republican Mike Rogers, 49 percent to 42 percent.

However, Franklin warned: “Polls are not perfect predictions of outcomes.

“We could see those close races go either way, either due to polling errors or due to voters moving just a little more in one direction or the other.”

In Alaska, there is also a complication: a legal dispute that could delay the result of a Senate race.

What is happening in Alaska’s Senate race?

The battle for Alaska’s seat could continue in court after voting closes on November 3. The dispute centres on two candidates named Dan Sullivan: the incumbent Republican senator and an independent candidate with the same name, who is also registered as a Republican.

Trump has accused Democrats of recruiting an independent candidate to confuse voters and take support away from the Republican senator.

“It was a scheme. It was an election fraud. Total election fraud,” Trump said.

The Department of Justice has taken legal action over the dispute, while Alaska Democratic candidate Mary Peltola denied the accusations.

“I feel like this is yet another diversion from the issue that Alaskans want to talk about, which is affordability,” she said.

Global News Insight’s US correspondent Alan Fisher said the dispute could have consequences beyond Alaska if the Senate’s control depends on the result.

“If this becomes the key seat in the battle for the Senate, we might not actually know who has control there for several days, maybe even weeks after November 3,” Fisher said.

What has happened on the campaign trail in the past 24 hours?

Trump travelled to South Carolina to campaign for Republican senator Darline Graham – sister of the late Senator Lindsey Graham – who is running against Annie Andrews in a close race.

In Rock Hill, Trump encouraged voters to cast their ballots and cautioned his supporters not to take the election outcome for granted. Trump said Darline Graham was in the lead but that he still had to campaign there. “In politics you never know, right? So you got to get out and vote.”

He also addressed his supporters directly, asking the crowd to pretend that he was on the ballot.

“And I am on the ballot because all of these things that we’ve done, all of these incredible successes that we have,” he added.

In Texas, Vice President JD Vance attended a rally in Weatherford, near Dallas, alongside Republican Senate candidate Ken Paxton, as Republicans called on supporters to vote.

“Texas ain’t surrendering. Texas is not becoming California. It’s going to stay Texas, ain’t that right?” Vance told supporters.

Well-known Democrats have also joined the campaign trail.

On Wednesday, former Democratic President Barack Obama gave a speech in Georgia supporting Senator Jon Ossoff, criticising Trump’s management of the economy and his approach to the war on Iran.

When Global News Insight asked about Obama’s visit, Ossoff’s Republican opponent, Mike Collins, said it showed “the desperation of Jon Ossoff, because he knows he’s losing”.

“If he was winning so big, he wouldn’t have brought anybody in,” Collins said.

Democrats also campaigned in Texas and Georgia on Thursday.

In Dallas, Senate candidate James Talarico held a rally as part of his final campaign tour, while former Vice President Kamala Harris joined Ossoff at Clark Atlanta University, urging young people to vote.

Harris also campaigned in Macon, Georgia, where she criticised the Trump administration over rising living costs.

“We have a moment now to turn pain into purpose,” Harris told Democratic volunteers. Harris also urged supporters to participate in local and statewide contests.

Later, at Clark Atlanta University, she asked students to stay engaged.

“Don’t overlook those races, because those are the folks who make decisions about your life every day,” she said.

What happens next on the midterm campaign trail?

A day after cancelling both of his appearances to hold telephone rallies, Trump has brought his campaign rallies back in Kansas and Iowa.

According to a source close to the Trump administration, the president will attend both events in person on Sunday, rather than going to Kansas on Saturday and then to Iowa on Sunday as was originally planned.

The source said the schedule had been altered so as to include more telephone rallies, which, in turn, enabled Trump to campaign virtually in several states.

The change occurred after Trump told reporters on Thursday that he did not see the need to go to Kansas, where the Republican Senator Roger Marshall is running against Democrat Adam Hamilton.

“I don’t feel I have to go to Kansas,” Trump said.

When a Reuters reporter asked whether the decision had anything to do with fatigue from travelling, Trump rejected the suggestion. “I feel perfect,” he said, before insulting the reporter.

Trump is also scheduled to hold a rally at the Ocean Center in Daytona Beach, Florida, on Friday at 23:00 GMT.

At the same time, Harris is due to address the Fulton County Democratic Party’s Fulton Forward dinner in Atlanta, Georgia.

Vance had planned a news conference with the White House Task Force to Eliminate Fraud in St Cloud, Minnesota, on Friday, but the visit was cancelled on Thursday. No reason was immediately given.