Sen. Tim Kaine (D-Va.), right center, is seen before a Democratic caucus meeting on Capitol Hill on Nov. 16. (Matt McClain/The Washington Post)

If the world didn’t know that Sen. Tim Kaine had just lost the vice presidency, a crushing defeat for the man, the Democratic Party and millions of American voters, nothing about his demeanor would give it away.

Smiling broadly, Kaine sat in his Senate office Thursday with the air of a man who had just won the lottery.

“I’m disappointed because I think I would have done a good job and I think Hillary would have been a great president, but I have a job to do here that in some ways may have gotten more important,” he said, bluegrass music playing in the background.

He ruled out a run for the White House in 2020 but will seek reelection in 2018, and Republicans are gunning for him. They are bolstered by a sense of dominance over American politics not felt since 1928 and believe they have a deep bench in Virginia.

“I’m assuming it’s going to be the hardest race I’ve ever run,” he said. “Presidential elections we do well. Off-year elections are tough.”

While introducing Hillary Clinton at her concession speech on Nov. 9 in New York City, Sen. Tim Kaine (D-Va.) drew cheers and applause when he quoted William Faulkner's words, "They kilt us but they ain't whupped us yit," as a way to encourage Democrats to move forward. (The Washington Post)

Pressed repeatedly, Kaine did not want to talk about what went wrong for Democrats this election.

“While I have some thoughts, I’m not objective about it,” he said.

Joining the ticket just three months before Election Day, Kaine couldn’t have had much say in strategy or the contours of the race.

He said Hillary Clinton ran into historic head winds trying to be the first female president and noted that only two Democratic presidents were elected following a two-term Democratic presidency — Martin Van Buren and Harry S. Truman.

Kaine, chosen in part because of his ability to communicate with Latino voters in fluent Spanish, offered no explanation for why the campaign didn’t win more Hispanic votes, except to say that no minority group is monolithic.

He said he understood why daily protests continue around the country more than a week after an election in which Clinton won the popular vote but Donald Trump won the office.

“I view it as people are afraid, and I think they have reason to be afraid,” he said, adding that he will go to battle over what he called the “normalization” of ­bigotry that he sees in President-elect Donald Trump’s appointment of Stephen K. Bannon as his chief strategist.

Kaine said he had no advice for protesters other than to encourage them to get involved in politics at the state and local level. “Look, civil disobedience has an important role in the history of this country,” he said. “I’m not encouraging folks, and I’m not discouraging them.”

Kaine said he always thought there was a chance he and Clinton could lose, but on election night, the results from the conservative Richmond suburb of Chesterfield, where Trump had a relatively weak showing, convinced him that they would win.

It hadn’t occurred to him, he said, that Democrats could win Virginia by a bigger margin than President Obama did in 2012, and win the popular vote by more than 1 million votes, and still lose.

Kaine moved to Virginia’s capital city and served as Richmond’s mayor, as well as lieutenant governor and governor, in hopes of making the state more progressive, he said. He had never lost an election.

Kaine said he had felt an “interesting set of emotions” once it became clear that Trump was surging ahead in the electoral college count. Like much of the country, Kaine stayed awake past midnight to await the final results. Then he took a nap.

Late the next morning, he introduced Clinton with hastily prepared notes scrawled on a piece of hotel stationery. After the speech, his wife, former Virginia secretary of education Anne Holton, kept the paper for their children to cherish.

The William Faulkner quote he recited — “They kilt us, but they ain’t whupped us yit,” — was one he clung to when he lost difficult cases during his 17 years as a civil rights lawyer.

He and Holton spent the weekend in the Outer Banks of North Carolina, where they “kvetched” a bit but mostly reflected on the good things in their lives, he said. They will celebrate their 32nd anniversary on Thanksgiving Day.

On Tuesday, Kaine drove himself to Washington, returning to the predictable rhythms of the Senate and his Russell Building office.

On Friday, he plans to travel with Sen. John McCain (R-Ariz.) and other lawmakers to a national security forum in Halifax, Nova Scotia, a trip he has made every year as senator.

Kaine sits on the Foreign Relations and Armed Services committees, and although he’s not officially part of the leadership, he said he plans to vigorously defend principles such as the constitutional powers of Congress, which could be crucial under Trump.

Calling the Democratic Senate minority the “only emergency brake” on matters of fundamental values, Kaine said he is proud of his colleagues for focusing on Bannon and “not allowing the appointment of someone who has connections to anti-Semitism and white nationalism to be just normalized.”

But common ground could be found with the Trump administration over a sweeping infrastructure bill that was also a Clinton priority, he said.

He has said he would like to fashion his Senate service after retired senator John Warner (R-Va.), who spent 30 years in office.

Virginia Republicans had praised Kaine’s bipartisanship in the past but criticized his presence on the national ticket and his comment Thursday that he will seek reelection.

Virginia GOP Chairman John Whitbeck said the announcement suggests he’s inappropriately mixing government service and politics.

After nonstop travel to 40 states, Kaine relishes his return to home life in Northside Richmond, “where nobody calls me Senator.”

The day after the election, he and Holton flew back to Richmond from New York on the campaign plane.

After they said an emotional goodbye to the Secret Service officers with whom they had grown close, Kaine said, he climbed the back steps to his kitchen and puttered around for a few minutes before going into his home office.

Peering out the window, he watched the government vehicles pull away one by one.

A wave of emotion came over him, he said.

It was relief.