Supporters of a more interventionist Syria policy are cheering Hillary ClintonHillary Diane Rodham ClintonNo Hillary — the 'Third Way' is the wrong way The dangerous erosion of Democratic Party foundations The Hill's Morning Report - Presented by Facebook - Democrats see victory in a voting rights defeat MORE's pick of Sen. Tim KaineTimothy (Tim) Michael KaineDemocrats call on Biden administration to ease entry to US for at-risk Afghans Manchin, Sinema join GOP to sink filibuster change for voting bill Desperate Dems signal support for cutting Biden bill down in size MORE (D-Va.) for vice president.
"In March 2014, Senator Tim Kaine (now Hillary's VP) stood with us in the freezing cold at the Capitol to remember the thousands and thousands of children killed in Syria, mostly by Assad's barrel bombs," wrote Kenan Rahmani, a Syrian-American activist and law school graduate, on his Facebook page.
"Kaine as VP is the greatest source of Hope for Syria that has been seen in far too long of a time," another activist commented.
Clinton, the presumptive Democratic presidential nominee, tapped Kaine as her running mate on Friday.
Kaine, a member of both the Senate Armed Services and Foreign Relations committees, has been particularly critical of the Obama administration's handling of the Syria crisis and has supported the establishment of no-fly zones over the northern part of the country.
"I think you could still do the humanitarian zone," Kaine told defense reporters in October, a month after the Russians began air strikes in Syria to shore up President Bashar al-Assad's regime.
"It's kind of bad that you have 4 million people that've already left Syria, but there's another nearly 8 million that are internally displaced in Syria who could leave, and I think we could work that out with Russia," he said on Oct. 29.
Kaine said he didn't believe Russia would interfere with safe zones, since there are already several United Nations Security Council resolutions calling for cross-border delivery of humanitarian aid.
"It's never really been implemented, and the only way it could be implemented is frankly with a little bit of military muscle," he said. "If we don't do that, I think you're going to continue to see this outflow of refugees, which is very, very challenging."
Kaine also signed a letter in April 2015 with Sens. John McCainJohn Sidney McCainThese Senate seats are up for election in 2022 Redistricting reform key to achieving the bipartisanship Americans claim to want Kelly takes under-the-radar approach in Arizona Senate race MORE (R-Ariz.), Lindsey GrahamLindsey Olin GrahamSenators introduce bill aimed at protecting Ukrainian civilians Kyrsten Sinema's courage, Washington hypocrisy and the politics of rage Hillicon Valley: Amazon's Alabama union fight — take two MORE (R-S.C.) and Dick DurbinDick DurbinEffort to overhaul archaic election law wins new momentum Senate panel advances bill blocking tech giants from favoring own products Manchin, Collins leading talks on overhauling election law, protecting election officials MORE (D-Ill.) calling for the establishment of at least one safe zone.
The administration has balked at creating a no-fly zone in Syria over concerns it could be considered an act of war, its legal rationale and because it could be too resource-intensive. The U.S. would likely have to enforce it with aircraft and a ground force.
Clinton, on the campaign trail, has also called for establishing a no-fly zone in Syria, and some of her top foreign policy advisers support striking the Assad regime if it continues to violate a cease-fire.
But one of her top advisers recently said he "didn't know" if Clinton would push for a no-fly zone if elected and stressed that there would be continuity on foreign policy following President Obama.
"The instinct is not going to be to come in and say, 'Everything's broken, we just need to do the opposite,' " Derek Chollet, a former top Pentagon official and senior adviser for security and defense policy at The German Marshall Fund, said last week.
"She's talking about looking at things like a no-fly zone, but we have a de facto no-fly zone over a big chunk of Syria today ... so we'll see," said Chollet, who recently published a book in defense of Obama's foreign policy called "The Long Game."
Kaine has also long called for the White House and Congress to work together to authorize the war against the Islamic State in Iraq and Syria since the U.S. began its air war against the terrorist group in 2014. He's been critical of the administration's claims that U.S. troops aren't in combat in Iraq and Syria.
Kaine also has a son who is an active-duty Marine.