Perriello is challenging the state's lieutenant-governor, Ralph Northam, in the primary.
The general election is scheduled for November 7.
Virginia's gubernatorial contest has received widespread national attention as the swing state is one of only two states electing new governors this year. Virginia parties often choose candidates in conventions rather than primary elections. He also has scored a slew of endorsements - having racked up the support of 67 of the 87 Republican members of the state General Assembly, a majority of the members on Republican State Central Committee and over 30 local party chairs, according to his campaign.
"I think the midterm elections and statewide elections are very critical to the national issues", said one voter.
The former congressman from Charlottesville made his anti-Trump message a priority early on, and he told NPR that was a big reason why he chose to get in the contest. Although Stewart's emissions may have inflicted further damage to the Republican brand, the party should emerge united - although, thanks to Trump, without the energy of Democrats.
Gillespie's ascendancy in the state party is also the latest step in a decades-long Beltway-ization of Virginia politics. Northam supports the pipeline project and is seen as more moderate-he voted for George W. Bush for president, twice.
"I started working at the age of 12 in my family grocery store stocking shelves and sweeping floors and bagging groceries", Gillespie said.
"I'm your typical presidential-only voter, and we got to a place like this because people like me let it get there", the owner, 54-year-old David Payne, responded.
The Democratic primary in Virginia is expected to be close, as Perriello has gained ground on Northam with the help of prominent national Democrats.
"If Tom wins, the political pundits will talk about progressives on the rise in 2017 and 2018 - and the resistance being strong", actor and activist Mark Ruffalo said in an email fundraiser Sunday.
Voters head to the polls Tuesday in Virginia's primary contests for governor, with the white hot Democratic contest coming down to a choice between heads and hearts. Perriello asked, referencing a policy he and Northam support but Republicans in the legislature oppose. Leah Greenberg, one of the two founders of the Indivisible, used to work for him on the Hill; Mr Perriello officiated at her marriage to the other founder, Ezra Levin. The former chairman is backed by most of the state party establishment, and has the fundraising advantage.
Gov. Terry McAuliffe has cast his ballot in Virginia's primary. He says all those miles have given him a broader understanding of the state and what he says should be the singular focus of the next lieutenant governor - jobs. "Northam, a doctor, has upped his attacks on Trump, calling the President a "'narcissistic maniac" in an ad last month. Gillespie, who enjoys the backing of most GOP state lawmakers, wants to put a share of future state revenue growth toward a modest income tax rate reduction.
Stewart has run a controversial campaign, pledging to fight the removal of Virginia's Confederate memorials and highlighting his loyalty to Trump and his policies.