WASHINGTON — It was on Barack Obama's third trip to Missouri in 2006 to help Claire McCaskill win a Senate race that she urged him to run for president.
"We're talking about it," he confided after a rainy Sunday night rally in St. Louis, two days before the 2006 election. "Win on Tuesday and we'll talk more."
McCaskill did win, and she and Obama did talk. They became Senate allies and friends. A year later he was a presidential candidate, and she provided a pivotal endorsement. She quickly emerged as one of his most visible and nimble defenders.
"It's very flattering," McCaskill said. "I don't want to abuse it, and I'm still, frankly, a little bewildered about how all it all happened."
McCaskill was at first-lady-in-waiting Michelle Obama's side at the second presidential debate. Behind the scenes, McCaskill conferred from time to time with the campaign brain trust, offered advice when asked and shared occasional e-mails with the candidate about how things were going.
She downplayed any special inner-circle status — "these guys didn't need my advice" — but any list of Obama insiders who are said to have the ear of the president-elect has to include the freshman Democratic senator from Missouri.
"She was probably the most reliable surrogate, even in contentious settings like going on Fox News, even in times when the narrative wasn't even great, like the Reverend Wright turmoil," said Josh Earnest, an Obama campaign spokesman.
It's been a wild and heady ride for the outspoken McCaskill, who grew up in a household where Harry S Truman was revered and her Halloween greeting back in 1960 was "Trick or treat. Vote for JFK."
Now party leaders from coast to coast recognize her. Bookers for political talk shows have her on speed dial.
"She goes from a backbencher just learning her role to someone who now can be one of the leaders of the Obama agenda in the Senate, somebody who will be looked to as a bellwether," said Brian Darling, the director of Senate relations at the conservative Heritage Foundation and a former Senate Republican aide.
People who've worked with both Obama and McCaskill said that Obama saw in her someone who wasn't wedded to political dogma, who preferred practical solutions to sometimes fruitless partisanship. McCaskill saw in him an inspirational leader.
In the marbled corridors of Capitol Hill, where phrases such as "my esteemed colleague" and "my good friend" are little more than tools of decorum, confidants of both said that they just genuinely liked each other.
The event that catapulted McCaskill into the campaign's inner orbit was her endorsement in January, five days after Obama lost the New Hampshire primary to New York Sen. Hillary Clinton. McCaskill was the first Democratic woman in the Senate to back him.
She was a loose brick in what had been expected to be a solid Democratic wall of support for Clinton from her female colleagues.
Here was a senator from a key swing state whose own success had been fueled by votes and money from women — whose mother had been the first woman elected to the Columbia, Mo., city council — and she was rejecting the first woman who had a good chance of becoming president.
"Senator Obama understood very clearly the risk she took," Earnest said. "Her endorsement was really, really important, being a woman, when he was in a contested primary with the most popular woman in the Democratic Party."
McCaskill first met the senator from Illinois in the spring of 2005. Senate Democrats had invited her to Washington in hopes of persuading her to run against Republican Sen. Jim Talent in 2006.
She was Missouri's state auditor at the time — just coming off an unsuccessful candidacy for governor the year before — and a former state legislator and county prosecutor.
One by one, a parade of leading senators made their pitch, including Edward Kennedy of Massachusetts, Joe Biden of Delaware, Patty Murray of Washington and Obama.
McCaskill said Obama was the only one who talked about the personal side of being a senator.
"He was already kind of iconic," she said. "I assumed he'd show up with an entourage. He showed up by himself and immediately started talking about the impact on your family. We talked about my kids and his kids. He understood what I was worried about."
Once she was elected, she worked with Obama on ethics-policy revisions and correcting problems at Walter Reed Army Medical Center. Their staffs were close, regularly checking with each other on their bosses' political temperatures on upcoming bills.
McCaskill wanted to endorse Obama as soon as he entered the presidential race in February 2007. She'd been a senator for barely a month.
Her staff and colleagues waved her off. Why risk alienating three senior senators — Clinton, Biden and Christopher Dodd — who were also in the race?
After she did publicly back him, the campaign dispatched her to key states and to the political talk-show circuit. "I very rarely said no," McCaskill said.
She still pinches herself and feels "grateful and blessed" for the role she played. In the Senate, she expects to be in a position to offer Obama informal advice, but only if he asks for it.
Chances are that he will.
MORE FROM MCCLATCHY