Now, Gillespie is running for governor, and his commitment to a big-tent party is being tested in President Trump's America.
In the campaign's final stretch, Gillespie's paid advertising has focused heavily on the threat of violence from the Latino gang MS-13, an issue he has tried to tie to his Democratic opponent, Lt. Gov. Ralph Northam. He also has vowed to preserve the state's Confederate monuments, and he attacked Democrats for restoring the rights of felons who served their time — and who are disproportionately black.
The victory of Trump — who campaigned on a hard-line immigration platform and repeatedly disparaged minorities — upended conventional GOP thinking about the value of a big-tent approach.
A Gillespie victory in a diversifying Virginia — where a Republican hasn't won statewide since 2009 — would cement the value of running hard to the right on cultural issues, political observers and strategists say.
"I think [Gillespie has] realized that the big tent is slowly becoming a yurt," said Jennifer Duffy, who tracks gubernatorial races for the nonpartisan Cook Political Report. "We are going to see a lot more of this in 2018, especially in primaries."
Gillespie resists suggestions that his tone on issues affecting minority voters has changed. He says he lives up to his "for ALL Virginians" campaign slogan, mingling with voters at mosques, ethnic food festivals and black-owned barber shops. He has also tapped high-profile Latino surrogates to campaign with him: Sen. Marco Rubio (R-Fla.) and New Mexico Gov. Susana Martinez (R).
"I take my campaign to every corner of the commonwealth," he said in a recent interview.
On the trail, Gillespie is more comfortable talking about tax cuts and jump-starting the economy than race. And when he does approach the explosive issue, he strikes a measured tone.
Victims of MS-13 gang violence, he notes, are often immigrants. He says Confederate monuments should have historical context to ensure they don't glorify Virginia's slavery-defending legacy. And he acknowledges racial disparities in the criminal justice system.
But his campaign commercials and mailers on the same issues, which experts say reach a larger audience, strike a much harsher tone.
"His personal style is the big-tent Republican in him," said Bob Holsworth, a veteran observer of Virginia politics. "But the campaign has a strong dose of Trumpism."
Race took center stage in Virginia's elections after white nationalists descended into Charlottesville to support a Confederate monument, sparking violence that left many injured and one woman dead. Gillespie repeatedly denounced the group, but recent Democratic campaign literature links Gillespie to the white supremacists because he never explicitly condemned Trump for saying there were "very fine people on both sides."
While Gillespie says his MS-13 ads are about public safety, Democrats and immigration advocates blast the commercials — which include images of tattooed Latino men and the gang slogan "Kill, Rape, Control" — as stoking fears of minority criminals, and fact-checkers say they are misleading.
They may even have gotten Trump's attention: He tweeted an endorsement of Gillespie that echoed the false claims in the MS-13 ads against Northam. Earlier this week, Trump followed up with a set of tweets that said Gillespie would protect "our great statues/heritage."
And they were certainly noticed by former president Barack Obama, who delivered a scathing attack on the ads during a rally last week for Northam in Richmond.
Virginia Del. Jason S. Miyares (R-Virginia Beach) dismissed fellow Latinos who are critical of the ads. "I don't think they give enough credit to voters of Virginia that this is about criminal gangs; this isn't about Latinos," he said.
Gillespie recently brushed off criticism when callers to a radio show challenged the ads. "It's others conflating MS-13 and the immigrant community, not me," he said. "I'm making a very clear distinction."
Mike Madrid, a GOP strategist, says such ads are effective with some voters, but also alienate Latinos, the fastest-growing segment of the U.S. electorate. Most polls have shown Gillespie either tied with or narrowly trailing Northam.
"When you are behind, you have to shoot every arrow in your quiver," said Madrid, an expert on the behavior of Latino voters. "But you are creating generational problems to win short-term election cycles, and that's the California story."
In California, Gov. Pete Wilson, a moderate Republican who once backed immigration reform, campaigned for reelection in 1994 on a platform of denying state benefits to immigrants living in the state illegally.
Wilson handily won. But it was seen as a Pyrrhic victory that electrified Latino voters and permanently tarnished the GOP brand in a state that is now solidly blue.
Gillespie invoked Wilson in a 2006 warning to Republicans against immigration messaging that can be perceived as anti-Latino.
"Anti-immigration rhetoric is a political siren song, and Republicans must resist its lure by lashing ourselves to our party's twin masts of freedom and growth — or our majority will crash on the shoals," Gillespie wrote in an opinion piece for the Wall Street Journal.
He credited Republican Robert F. McDonnell's victory in Virginia's 2009 gubernatorial election to engaging Hispanic voters, who make up about 5 percent of the electorate, "instead of indulging in the anti-immigration rhetoric of past Republican campaigns."
Frank Sharry, executive director of the pro-immigration group America's Voice, said he was shocked to see Gillespie's evolution.
"Mr. Gillespie is putting his relatively good reputation on the line in a way that will tarnish him forever," Sharry said.
In recent years, the Republican Party has gone through a tumultuous journey on immigration issues — creating a tightrope for candidates.
President George W. Bush's attempt at comprehensive immigration reform, including a path to legal status, failed in 2007 — the same week Gillespie became a White House counselor. Gillespie also advised 2012 presidential contender Mitt Romney, whose loss resulted in an autopsy that urged the party to embrace comprehensive immigration reform.
But calls for more moderate positions receded as primary voters and activists demanded a tougher stance on immigration. They flexed their muscles in Virginia in 2014 when voters in the Richmond suburbs ousted Rep. Eric Cantor, then the House majority leader. In the 2016 GOP presidential primaries, past support for an immigration overhaul became liabilities for former Florida governor Jeb Bush and Rubio.
Gillespie almost became a victim himself when he nearly lost the Republican primary in June to Corey A. Stewart — a Trump acolyte who made defending Virginia's Confederate statues his signature cause and promised to crack down on illegal immigrants.
By September, Gillespie was adopting some of the same tactics for the general election.
If Gillespie wins, Republicans competing in the 2018 midterms will embrace his approach to racial issues, said Tom Steyer, a Democratic megadonor who has spent at least $3 million to elect Democrats in Virginia this year.
"Mr. Gillespie has descended to a very low level of division and racialization, and if it works, I think Republicans across the country are going to draw the conclusion that that's where they have to go," Steyer said.
In New Jersey, which is holding the nation's only other gubernatorial contest this year, the Republican candidate is airing a commercial focused on an undocumented immigrant who allegedly raped a child and shot four young people, and accuses the Democratic candidate of wanting to make the state a "sanctuary" for illegal immigrants.
Republicans this year have homed in on criticism of "sanctuary cities" — a loosely defined term that generally refers to jurisdictions that see immigration enforcement as a strictly federal responsibility and do not alert federal officials about someone who might be in the country illegally. They also will not hold suspected undocumented immigrants after they have completed a jail sentence for them to be picked up by federal authorities.
Gillespie's ads accuse Northam of casting a "deciding vote" against a ban on sanctuary cities. But Virginia does not have sanctuary cities, and Northam did not cast a deciding vote because the bill eventually passed the legislature and was vetoed by Gov. Terry McAuliffe (D).
Gillespie's sanctuary cities ads are not only targeted at ruby-red rural districts where he needs to turn out his base, but also geared toward moderate voters in purple Washington exurbs that are crucial for statewide victory.
Kilgore, currently finance chair of the state GOP, says the immigration ads he aired in 2005 are not comparable to Gillespie's advertising blitz.
"Ed has actually found a public safety issue that resonates not just with the immigrant community, but with soccer moms and others in Northern Virginia," Kilgore said.
Gillespie and his surrogates frequently highlight eight recent killings in Northern Virginia that authorities believe are related to MS-13. And the candidate often mentions that he hears concerns about the gang from voters in Northern Virginia, including from an unidentified "Hispanic faith leader."
At a recent town hall in Leesburg — in the swing Washington exurb of Loudoun County — Gillespie ended his speech by talking about the threat of MS-13 gang violence, stressing that he joined local law enforcement for a ride-along and that he would work with Rep. Barbara Comstock, a Republican who represents the area in Congress, to increase funding for a regional gang task force.
Among the attendees was Celia Meyer, a 27-year-old new mother who lives in nearby Ashburn. She prefers not to discuss Trump and says Gillespie's call to reduce taxes is enough to win her vote. But she also said his criticism of sanctuary cities hits upon valid concerns.
"There's nothing wrong with trying to make our country safer, especially when people aren't supposed to be here in the first place," Meyer said.
Others resent the idea that Gillespie's criticism of sanctuary cities amounts to a hard-right immigration stance.
"Calling him racist at every turn is stupid, and saying 'You don't want violent gangs' means 'You hate immigrants' is stupid," said Theseus Schulze, a 23-year-old law student who voted for Libertarian Gary Johnson in November. "Him saying 'no sanctuary cities' is a totally moderate position that most people support, but Democrats go crazy and call him racist."