Democratic US presidential candidate Kamala Harris and her running mate Tim Walz will campaign together on Wednesday in Georgia, a state that Democrats narrowly won in 2020 and could play a decisive role in this year’s election.

The election race has dramatically changed since Harris became her party’s candidate last month, and she hopes to galvanise Black voters who make up about one-third of Georgia’s electorate and will be crucial in the effort to win there.

Harris and Walz will take a bus through southern Georgia, home to some of its largest Black populations and where the campaign has added staff and opened field offices.

Before President Joe Biden dropped his reelection bid last month and endorsed Vice President Harris, polls showed Republican candidate Donald Trump with a clear lead in Georgia, and some Black voters were disillusioned with Democrats.

Since then, however, Harris has steadily gained ground in national polls and has been boosted by well over $500 million in donations.

The latest polls compiled by FiveThirtyEight show Harris just behind Trump, 46.0 per cent to 46.6pc in Georgia, compared to about a five-point lead for Trump before Harris entered.

Before the 2020 race, Georgia last backed a Democrat for president in 1992.

If elected, Harris will be the first female president in US history. As a Black and South Asian woman, she is seeking to shore up support for Democrats among Black voters and motivate new groups of voters.

Harris is expected to focus on the economy and abortion rights during the Georgia trip, including a pledge to lower consumer costs, a campaign official said.

The tour will culminate with a Harris rally in the Savannah area on Thursday.

“Campaigning in this part of the Peach State is critical as it represents a diverse coalition of voters, including rural, suburban, and urban Georgians — with a large population of Black voters and working-class families,” the Harris campaign said.

It is Harris’s second Georgia trip since she became the Democratic candidate. A rally in Atlanta earlier this month featured hip-hop star Megan Thee Stallion and drew more than 10,000 people.

Harris, 59, pledged then that Democrats will win the state which has 16 electoral college votes and is one of several swing states that can lean either to Republicans or Democrats. Democrats won it by less than 12,000 votes in 2020.

Republicans have dramatically ramped up spending in Georgia and the Republican-controlled state election board added a new rule that voting rights advocates say could delay certification of the vote in November.

Trump, 78, said in a social media post last week that winning Georgia “is so important to the success of our party, and most importantly, our country.”

He is expected to campaign in the state several more times before Election Day on November 5.

Recent national polls have shown Harris building a small lead over Trump since she entered the race on July 21.

A new Reuters/Ipsos poll on Tuesday showed that Harris has eroded Trump’s advantage on the economy and crime.