Majority of African-Americans still back Obama, which could be crucial in midterms, but in Kentucky some are switching sides

The enormity of the task facing the Democrats in the midterm elections is all too evident at the Midwest church of Christ, which lies in a predominantly black neighbourhood in Louisville. Its pastor, the Reverend Jerry Stephenson, is a registered Democrat but he will be voting in the US Senate race for the Republican candidate and Tea Party favourite, Rand Paul.

Stephenson, 61, is furious over the school drop-out rate among African-American children in his neighbourhood – which has one of the highest crime rates in the city, especially among teenagers – and across the nation.

He felt pride when Barack Obama became the first black US president, but that pride has been tempered by a growing belief that he is not up to the job. "There has to be change that we can not only believe in," he said, echoing an Obama campaign slogan, "but that we can see."

The pastor is so angry that he has embraced the Tea Party movement, in spite of it being overwhelmingly white and repeatedly accused of racism. He speaks at their rallies across Kentucky, delivering fiery speeches in the cadences and rhythms common among southern black preachers.

Stephenson is in a minority of African-Americans likely to back the Republicans, estimated at little more than 10%. African-Americans traditionally back the Democrats and Obama won 95% of their vote in 2008. That loyalty appears to be holding: a Pew Research Centre survey in September found he had an 88% approval rating among black people, more than double that of the white population.

The question for Obama is whether they will turn out in record numbers again to vote Democrat or whether they will stay at home, either out of apathy or disillusionment with the slow economic recovery.

With less than a fortnight to the midterm elections, the Democrats are targeting African-Americans across the country, spending $3m (£1.9m) on adverts aimed at black radio and television stations, hoping that they might make the decisive difference in key contests. The Republican party, in an attempt to woo the African-American vote, is fielding 14 black candidates.

Some political analysts, such as David Bositis, senior political analyst at the Joint Centre for Political and Economic Studies, said in a report last week that there could be a high turnout which could rescue the Democrats in some contests.

But others are sceptical. Merle Black, one of the leading academics on the politics of the south, who is based at Emory University in Atlanta, said there was always a big drop-off between presidential and midterm elections and he did not expect this year to be any different.

Polls in Kentucky close early on 2 November and it will be one of the first results in. If the Republicans fail to hold the state, their chances of securing a majority in the Senate are remote.

It is a surprisingly close contest, given that polls suggest massive Republican gains elsewhere, and is being bitterly fought, one of the ugliest campaigns in America.

A debate at the University of Louisville on Sunday night between Paul, 47, an opthalmologist, and his Democratic rival, Jack Conway, 41, the state's attorney-general, was a nasty affair. Paul took offence at a Conway advert that questioned his Christianity and suggested that as a student Paul was part of a group that had tied up a woman and had her bow in front of a false idol, the Aqua Buddha. Paul left the stage without shaking hands.

African-Americans attending the debate mostly favoured Conway, but there were Paul sympathisers too. One of them, Martina Kunnecke, 57, a researcher and freelance writer from Louisville, said: "I am a lifelong Democrat but I am leaning towards Rand Paul. The Democratic party has become so corrupt. I am disenchanted with the Democratic party machine. Real people can't aspire to office. You have to have money and be connected."

Kunnecke has attended Tea Party meetings – "my friends thought I was bananas" – and is disappointed in Obama. "It is very sad. He was not up to he job," she said. She would have preferred Hillary Clinton.

Paul was one of the first Tea Party candidates to achieve national fame and favours abolition of federal departments such as education – handing control back to local communities – and the removal of many social security benefits.

He argued in an interview with the cable news channel MSNBC in May that the federal government should not be telling businesses who they could serve or not serve, saying he opposed the civil rights legislation that ended segregation in the south in the 1960s.

This created a firestorm across the US, particularly among African-Americans, forcing Paul to backtrack, saying the civil rights act was necessary because of "an overriding problem in the south so big that it did require intervention".

His remarks angered a lot of black voters, although it did him little harm in the predominantly white rural districts of Kentucky that are likely to deliver for him on election day. In a poll conducted by Louisville's Courier-Examiner in May, 32% agreed with Paul that businesses should be allowed to consider ethnicity when deciding who they serve.

Milton Seymore, pastor at the Energised Baptist church, on a desolate stretch of road surrounded by strip clubs on the outskirts of Louisville, is not persuaded by Paul's public reversal on the issue. He insisted it was no slip of the tongue and that Paul had expressed similar views in the past.

The organiser of a boycott of businesses in Louisville seven years ago in a civil rights dispute, Seymore, 64, described Paul as an embarrassment to Kentucky for his views on the civil rights act. "That he wants to take the state of Kentucky back to the era of Reconstruction and Jim Crow is unthinkable," he said. "You would think a lot of people of his age and experience would understand the fight of African-Americans in this country."

He characterised Obama as a victim of the economic recession inherited from George Bush. But he understood people's impatience: "There are jobs trickling in. It is a slow process. African-Americans were the last to be hired and the first to be fired." Nonetheless, he urged them to vote in a show of solidarity with Obama.

Four miles away, at the Midwest church, Stephenson is unrepentant about his support for the Republicans. "I have been persecuted for what I have said. People say I have lost my mind, that I am a turncoat," he said.

He is adamant that Paul is no racist and that the country needs independent thinkers. "This country needs a revolution."