By James Coomarasamy
BBC News, Lancaster County, Pennsylvania
Lancaster County, Pennsylvania, should be McCain country.
Rev Hagee's (L) endorsement later proved embarrassing for Mr McCain
About 70% of its residents are registered Republicans, and George W Bush won two-thirds of the votes here in 2004.
But speaking to concert-goers at the Witness Christian Rock Festival, which was held in the county last weekend, you get a very vivid sense of the hurdles John McCain faces.
Many of the people there describe themselves as Evangelical Christians, part of a core Republican constituency, which was successfully mobilised by the Bush campaign four years ago.
But when you ask whether this year's presumptive Republican nominee has their support, few give a clear answer.
"The easy thing for a conservative would be to vote Republican, and I've always voted that way," says Scott, a man in his thirties, with a bare chest and prominent crucifix.
"But this isn't an easy election. I'm bothered by a lot of what people I trust have told me about John McCain."
This mistrust of John McCain has its roots in his uneasy relationship with evangelical leaders.
In its most famous manifestation, he referred to televangelists Jerry Falwell and Pat Robertson as "agents of intolerance" during his 2000 run for the White House.
That helped to cement the Arizona senator's reputation as an independent voice, but, as he prepared to run in 2008, he began to change his tune.
In 2006, he gave the commencement speech at the late Reverend Falwell's Liberty University in Virginia and in 2007, he referred to the United States as a "Christian nation".
And this year - with the election campaign in full swing - he touted the endorsements of televangelist John Hagee and prominent Ohio pastor Rod Parsley.
But this brought problems.
Even as his Democratic opponent, Barack Obama, was being forced onto the defensive by the fiery sermons of his former, long-time pastor, Jeremiah Wright, John McCain had his own explaining to do.
John Hagee, who was known to have made offensive comments about Roman Catholics had also - it emerged - referred to the Holocaust as "God's will", while Rod Parsley had called Islam "an anti-Christ religion that intends through violence to conquer the world".
Under pressure, the presumptive Republican nominee repudiated both endorsements.
According to Jacques Berlinerblau, Professor of Jewish Civilisation at Georgetown University and writer on the role of religion in presidential politics, the whole episode showed that Mr McCain's advisors had a tin ear for religion.
"The McCain team went after these endorsements apparently not knowing who these people were, but also - more importantly - overestimating their ability to bring in the votes," he says.
"And they completely lost their major trump card: Senator Obama's association with Reverend Wright, which upset many blue-collar, white voters, who Senator McCain needs to win this election."
A stumble, then, but perhaps not a fatal one.
Although evangelical leaders have still not embraced John McCain, he is far closer to them on social issues such as abortion and gay marriage than Mr Obama.
Mr Obama could win more evangelical voters than previous Democrats did
This is how Dr Richard Land, President of the Ethics and Religious Liberty Commission of the Southern Baptist Convention puts it:
"What I've heard over and over again from social conservatives, Southern Baptists - pastors and non-pastors - is 'John McCain wasn't my first choice. In some cases he wasn't my second or even third choice. But I'd rather have a third-rate fireman than a first-class arsonist'. And they look upon Barack Obama as a first-class arsonist when it comes to the issues that matter to them."
But those issues - and priorities - seem to be changing.
At the Witness Festival in Pennsylvania, for example, huge posters showing a starving African child dominated the grounds, vividly illustrating the extent to which issues such as poverty and global warming have risen up the agenda of younger evangelicals.
And the Obama camp is hoping that this will help them prise these voters away from John McCain.
They are relying both on their candidate's comfortable use of religious rhetoric and the efforts of their well-developed Christian outreach team, created, in part, to counter one of the Democrats' long-standing problems - talking about religion.
Although, in a sign of the extra challenges faced by Senator Obama, part of their work has been to counter the widespread rumours that he is a Muslim.
At the moment, though, the Obama team seems confident that it is making inroads into this core Republican constituency, while remaining wary of the predictions from some quarters that their candidate could win as much as 40% of the evangelical vote in November.
An unlikely figure, perhaps, but food for thought for the McCain campaign, as it tries to balance appealing to those prized independent voters, with shoring up the support of the Republican base.
Even at this early stage of the general election campaign, it is proving to be a tough balancing act.