NEW YORK, July 22 (UPI) -- Hillary Clinton formally locked up the Democratic presidential ticket late Friday -- announcing her pick of Virginia Sen. Tim Kaine as the party's vice presidential candidate this fall.
Clinton had been expected to name her V.P. candidate all day Friday. The news finally arrived online Friday night.
"I'm thrilled to announce my running mate, Tim Kaine, a man who's devoted his life to fighting for others," Clinton stated on Twitter.
The former secretary of state elaborated on her selection on her Facebook page.
"Tim's a man of relentless optimism who believes no problem is unsolvable if you're willing to put in the work," she stated. "That commitment to delivering results has stayed with him throughout his decades-long career as a public servant."
Kaine, a popular bilingual senator from a swing state, beat out Agriculture Secretary Tom Vilsack, New Jersey Sen. Cory Booker and Massachusetts Sen. Elizabeth Warren for the second slot on the Democratic presidential ticket.
Clinton made the official announcement three days before the start of the Democratic National Convention, which begins Monday in Philadelphia.
"I didn't make this decision lightly," Clinton added. "I've had the privilege of seeing two presidents and two vice presidents up close, and I wanted to pick someone who will be able to give me their best advice, look me in the eye, and tell me they disagree with me when they do.
"But what matters most is a simple test that's not easy to meet: whether the person could step in at a moment's notice and serve as president."
Former President Bill Clinton reportedly endorsed Kaine as the vice presidential candidate and has stressed the importance of winning his home state of Virginia, as no candidate since 2000 has won the White House without it.
The long-awaited pick, though, may not be catching fire in the Democratic ranks as hotly as Clinton had hoped for. Many party liberals, particularly those aligned with Sen. Bernie Sanders, voiced substantial objection to a senator who's viewed widely as a moderate.
"Our presidential ticket cannot beat the billionaire bigot by simply being not Donald Trump," said Charles Chamberlain, executive director of the liberal advocacy group Democracy for America, in a statement. "To win in November, our ticket needs to have an unquestionably strong record in the fight against income inequality, one of the defining issues of the 2016 election."
Kaine has expressed vocal support for free trade pacts that have become a central economic issue in the campaign, and one on which Clinton has had a complicated history. She voted against the only free trade deal to come before the Senate in her eight years there, the Central American Free Trade Agreement, or CAFTA, but Bill Clinton negotiated and pushed through the precursor, the North American Free Trade Agreement. Now, more than six in 10 Americans believe NAFTA has resulted in U.S. manufacturing jobs to move to Mexico, a partner in the agreement.
Additionally, as secretary of state, Clinton supported the Trans-Pacific Partnership, a trade deal negotiated by President Barack Obama. Now as a candidate she has indicated she would be unlikely to support it in its present form because she said it lacks sufficient environmental and labor protections for U.S. workers from cheaper-cost Asian nations.
Kaine voted to fast-track approval of TPP in the Senate last year and has defended NATFA.
Trade is a singular issue where Trump's unorthodox brand of populist conservatism meets up with that of Clinton's primary opponent, the democratic socialist Sanders. Both men railed against free trade deals as job-killers throughout the primary.
Liberals such as DFA's Chamberlain have held out hope Clinton would use the VP selection to offer an olive branch to liberals.
Some liberals had hoped the pick would be Warren, Sanders or Ohio Sen. Sherrod Brown -- although each posed their own compatibility issues.
Warren and Clinton do not enjoy a close personal relationship and Warren's steadfast opposition to large Wall Street banks, while immensely popular with the liberal base, could prove a detriment to Clinton's fundraising efforts in her adopted home state of New York.
Brown, who was widely seen as a more palatable option to Clinton personally, is weighed down by the political realities of his Senate seat. If Brown were to run as VP and win, it would mean handing Republicans his seat for at least the next two years because it would be filled via executive appointment by Ohio's Republican governor, John Kasich. Republicans are on the defensive trying to hold their Senate majority with far more seats to defend than Democrats in 2016, meaning handing away Brown's seat to the GOP could cost Democrats control of the entire chamber.
Some critics believe Kaine doesn't bring the sizzle needed by the Democrats to vie for voters impressed with Trump's no nonsense approach and get-it-done attitude.
"I have no doubt that Tim can do the job, and I want him by my side on the trail and in the White House," Clinton said. "But we're going to need your help to get there. So join me and Tim, and let's get to work and go win this thing."