The two current candidates in the Republican primary field, Businessman Shak Hill and former Navy Officer Howie Lind, have publicly shrugged Gillespie's candidacy off but he is already seen as the best (albeit still unlikely) candidate to unseat Warner. Gillespie's strengths lie in his fundraising ability and connections to powerful Washington Republicans.
After graduating from the Catholic University of America in Washington, D.C. Gillespie started out as a Senate parking attendant. He eventually went to work for the Republican National Committee and served as a longtime aide to House Majority Leader Dick Armey (R-TX). During his time with Armey, Gillespie also became one of the primary authors behind the 1994 Contract With America.
According to a 2001 profile of him in The New Republic, Gillespie got in early with George W. Bush's 2000 presidential campaign, first serving as an unpaid strategist. He rose through the ranks and eventually helped coordinate Republican strategy during the 2000 Florida recount. Over the next decade or so, Gillespie would also co-found the powerful lobbying firm Quinn, Gillespie and Associates. He served as a top adviser to President George W. Bush, helmed the Republican National Committee and co-founded American Crossroads GPS with Karl Rove.
In the last few years, Gillespie has remained active in Republican politics. He served as the chairman of Bob McDonnell's successful 2009 gubernatorial campaign, was an adviser on Mitt Romney's 2012 presidential campaign and most recently he served as the chairman of the Republican State Leadership Committee. Gillespie's jobs mostly required him to push positions of elected Republicans or the official Republican Party platform.
Experts say this could be advantageous in a run for the Senate.
"He doesn't have much of a legislative background at all," George Mason University Political Science Professor Michael McDonald told TPM. "He's been a spokesman for the Republican National Party of course, but he's never had to take any policy positions other than be a spokesman for his party and so he can craft his own persona to fit the electorate in Virginia."
But he's not completely a blank slate. Gillespie has come out as a supporter of comprehensive immigration reform, publicly said reducing federal spending should be a top priority and strongly argued that the GOP would never embrace marriage equality. The debt and gay marriage are unlikely to hurt him among Republican primary voters, but immigration reform could be another story. Additionally, Gillespie's background as a lobbyist and adviser to establishment Republicans means he's unlikely to win over support of powerful grassroots organizations like the Senate Conservatives Fund or FreedomWorks. The question for Gillespie, McDonald said, is whether he can shore up support among tea partiers.
"If the conservatives within the party aren't satisfied with Gillespie they may very well look to nominate somebody that would be more ideologically extreme or somebody that they know that has the more conservative, tea party credentials that they're looking for," McDonald said.
Former Mississippi Gov. Haley Barbour (R), who Gillespie served as communications director for when Barbour served as chairman of the RNC, suggested that his former aide is unlikely to wage a full-on tea party campaign.
"I don't know what he is going to do, but if he were to run I guarantee he would run the kind of campaign to win a substantial majority, not a narrow majority, that he would cast his net wide -- which is the right thing to do," Barbour told TPM. "Ed's a solid conservative but he is not a purist. He is someone who wants to see good policy adopted and he's not going to let the perfect be the enemy of the good."
In other words, a hypothetical general election between Warner and Gillespie is unlikely to be like the far right challenge Virginia Attorney General Ken Cuccinelli (R) waged against Terry McAuliffe.
Barbour also said Warner is likely to outspend Gillespie or any other candidate in the race.
"Mark Warner's going to have more money against whoever runs against him whether it's Ed Gillespie or somebody else," Barbour said. "However, the election is not about who spends the most money."
One opening Gillespie will likely try to exploit is Obamacare. The best polling for Warner came before the Obama administration's disastrous rollout of healthcare.gov. Warner has criticized the rollout of the law, but still supports Obamacare on the merits. Gillespie could hypothetically cut down some of Warner's lead by focusing on the Obama administration's health care law, pitting him with many red-state Democrats in a year of playing defense on the law.
Another small indicator that Gillespie is looking to take a different approach is that he's reportedly hired Chris Leavitt who ran state Sen. Mark Obenshain's (R) Virginia campaign for attorney general. That campaign, in contrast to Cuccinelli's, was mostly positive and strayed away from hammering the opponent on socially conservative issues. Obenshain may have lost, but the margin was razor-thin largely thanks to a smart campaign team.
Gillespie's lobbying and connections to powerful Republican lawmakers in the Virginia area are reason to believe he'll be the candidate most likely to compete with Warner on the money front. That alone won't assure Gillespie victory, but given the other factors it's enough to push political observers to say Gillespie has a chance. On Friday University of Virginia Center for Politics Director Larry Sabato's Crystal Ball team changed the race rating from Safe Democratic to Likely Democratic, something Gillespie will publicly agree with.
"I have concluded it is a winnable race," Gillespie said after addressing the Norfolk Republican Party recently. "I'm very touched that a lot of my friends and fellow Republicans in Virginia think I could be a good standard bearer for us."