But the tone at McCain's and running mate Sarah Palin's events during the past week had been turning toward the sour. Supporters had shouted "terrorist" and "off with his head" at the mention of Obama's connections to former Weather Underground member William Ayers, whose group bombed federal buildings in protest of the Vietnam War when Obama was a child. The two had worked together on community projects in Chicago, and Obama has denounced Ayers' violent past.
On Friday during a town hall-style meeting in Lakeville, Minn., a supporter told McCain that he feared what would happen if Obama were elected. McCain drew boos when he defended his rival as a "decent person and a person that you do not have to be scared of as president of the United States."
In another exchange, a woman told McCain that she didn't trust Obama because "he's an Arab." Shaking his head and taking the microphone from her, McCain replied: "No, ma'am. He's a decent, family man, citizen, that I just happen to have disagreements with on fundamental issues and that's what this campaign is all about."
McCain returned to that note of civility on Saturday as his quandary became clearer: He needed to excite his party's base without inciting them, challenge Obama while being an honorable opponent, and find a game-changing strategy for his faltering campaign without crossing the line.
When an anti-war protester interrupted him, McCain nervously watched what the crowd would do. The protester was hoisted on shoulders and McCain's supporters chanted "We want John." "You know, my friends, there's a perfect example of some people who just don't get it," McCain said to thunderous applause.
"As people are trying to stay in their homes, keep their jobs and afford health care, is what they want for us, to yell at each other?" he asked. "No. They want us to sit down together, Republican and Democrat, to work through this terrible time of crisis."
Just days ago, on the stump and in ads, the question was "Who is Barack Obama?" For the moment, that question was shelved.
"Which candidate's experience in government and in life makes him a more reliable leader for our country and commander in chief for our troops?" McCain asked. "In short: Who's ready to lead?"
McCain's most serious criticism of Obama on Saturday was over health care, not character. His advisers say that they will aggressively challenge Obama's record but will not to make it personal. The two are to meet for a third and final debate on Wednesday.
Unhelpful for establishing the tone McCain sought in Davenport was the Rev. Arnold Conrad, past pastor of the Grace Evangelical Free Church. His prayer before McCain arrived at the convention center blocks from the Mississippi River appeared to dismiss faiths other than Christianity and cast the election as a referendum on God himself.
"I would also pray, Lord, that your reputation is involved in all that happens between now and November, because there are millions of people around this world praying to their god - whether it's Hindu, Buddha, Allah - that his opponent wins, for a variety of reasons," Conrad said.
"And Lord, I pray that you would guard your own reputation, because they're going to think that their god is bigger than you, if that happens. So I pray that you will step forward and honor your own name with all that happens between now and Election Day," he said.
On the Net:
McCain campaign: http://www.johnmccain.com/
Obama campaign: http://www.barackobama.com/index.php