With five days to go before the United States midterms, Democrats are ahead in national polls, but several Senate races remain close.

President Donald Trump, former President Barack Obama and Vice President JD Vance were out campaigning on Wednesday in Ohio, Georgia and North Carolina, as both parties fight for control of Congress.

Here’s what to know:

What do the latest polls say about the US midterms?

Democrats lead Republicans by 51.4 percent to 43.2 percent, a gap of 8.2 percentage points, according to RealClearPolling’s national polling average.

But the national lead is not reflected in every Senate race.

In Texas, where Democrats haven’t won a Senate election since 1988, Democrat James Talarico leads Republican Ken Paxton with 48.5 percent to 46.7 percent, according to the poll aggregator.

In Michigan, Democrat Abdul El-Sayed has widened his lead over Republican Mike Rogers to seven percentage points, according to a Mitchell Research poll conducted for CBS Detroit.

The October 26-27 survey found El-Sayed leading Rogers 51 percent to 44 percent, up from a 4.2-point advantage earlier this month.

RealClearPolling showed a narrower race, with El-Sayed at 48 percent and Rogers at 46 percent.

Despite that lead, Democrats are continuing to campaign for support among young voters in Michigan.

“We need everybody and young people are a huge part of the coalition and could really be the difference-maker on November 3rd,” Will Lawrence, a Democratic candidate hoping to win Michigan’s 7th Congressional District from the Republicans, told Al Jazeera.

Democratic Congressman Maxwell Frost, who travelled from Florida to campaign for El-Sayed, said face-to-face conversations with voters were particularly important.

“Everyone’s seen the negative bigoted ads and Islamophobic ads, but what hasn’t happened is everyone hasn’t had person-to-person conversation about why Abdul is the right senator for Michigan,” he said.

Republicans are also trying to reach young voters, with one supporter telling Al Jazeera: “I think there’s definitely a movement that people don’t realise in Gen Z that is turning more conservative.”

Beyond Michigan, some voters told Al Jazeera they were frustrated with both parties.

“Each party wants to be in power and I think they’ll say what they think they want their voters to hear,” one voter said in Lexington, Kentucky.

Democratic strategist Joel Rubin described the midterms as a potential “protest election”, with many Democratic voters looking to limit Trump’s power.

“I think that overwhelmingly American voters who will vote Democratic are voting because they want to put a check on President Trump’s power,” he said.

Republican strategist Suhail Khan said Trump was losing support among a number of his own voters, who were frustrated by rising fuel prices, rents and mortgage costs.

“I keep voting and I’m independent, I vote both sides … I’m so frustrated and out of hope,” another voter said in Gettysburg, Pennsylvania.

Can Democrats take control of Congress?

Democrats are hoping to overturn Republican majorities in both chambers of Congress, but the Senate presents a bigger challenge.

They need a net gain of three seats in the House of Representatives and four in the Senate, where Republicans currently hold 53 of the 100 seats. Democrats hold 47, including two independents who caucus with them.

Democrats need to reach 51 seats to take control, but the path to a Senate majority is not simple.

“Even the most optimistic of Republicans will tell you that it’s going to be pretty tough for the GOP to hold on to the House of Representatives,” Al Jazeera’s Scott McLean said. “Different story when it comes to the US Senate, though.”

McLean said that even if Democrats win North Carolina and Ohio and hold on to their current seats, they would still be two seats short of the 51 needed for a majority.

Alaska and Texas could help close that gap. But Republicans are also hoping to win Michigan, where the race remains tight.

Taking control of the House of Representatives alone would still have significant consequences for Trump. If the Democrats flip the House, they can block parts of his legislative agenda and launch investigations into his administration.

They would also be able to call administration officials to testify before congressional committees, although the White House could challenge those demands.

What’s happened on the US midterm campaign trail in the past 24 hours?

Trump was in Ohio campaigning for Republican Senator Jon Husted, who is facing former Democratic Senator Sherrod Brown.

During the rally, Trump defended Republican gubernatorial candidate Vivek Ramaswamy following backlash over an advertisement featuring the estranged mother of his Democratic rival, Amy Acton.

Ramaswamy was being treated “very unfairly”, Trump said. “How the hell is that his problem?”

Trump also spoke about Jeffrey Epstein after protesters interrupted his speech, saying he had expelled the late sex offender from his Mar-a-Lago club two decades ago.

Meanwhile, in Georgia, former President Obama joined Democratic Senator Jon Ossoff and gubernatorial candidate Keisha Lance Bottoms.

Obama criticised Republicans for their reaction to his recent Cheesecake Factory joke about White House renovations, saying they were more concerned about that than the rising cost of living.

“These are not serious people. They don’t have solutions to actual problems,” he said.

Vance also rallied in North Carolina, where former Governor Roy Cooper is facing Republican Michael Whatley in the Senate race.

What’s next for Trump, Democrats and Republicans?

Trump is scheduled to campaign in South Carolina on Thursday at 16:30 GMT, before heading to Florida on Friday and Kansas on Saturday.

South Carolina is among the Republican-held Senate seats Democrats are targeting, although the party faces a difficult contest in a traditionally conservative state.

In Texas, Vice President JD Vance will hold a rally in Weatherford at 17:15 GMT, with Republican candidate Ken Paxton facing a close Senate race against Democrat James Talarico.

Talarico will also be campaigning on Thursday in Dallas, at 00:00 GMT on Friday (7pm Thursday local time).

Al Jazeera’s Phil Lavelle reported from Texas that Republicans are particularly concerned about turnout in rural areas, where 21 percent of registered voters had cast their ballots, compared with 24 percent in the more heavily populated metropolitan areas.

Meanwhile, former Vice President Kamala Harris is expected to campaign in Georgia, where Democratic Senator Jon Ossoff is defending his seat against Republican Mike Collins.

Georgia’s early in-person voting ends on Friday as both parties make their final push before Election Day.