On Tuesday, Youkilis had pulled ahead of Swisher in a race that has swung back and forth like some of those epic Red Sox-Yankees pennant races of past years.
Fans have until 3:59 p.m. ET on Thursday to vote as many times as they want at redsox.com and mlb.com.
According to a press release from MLB.com, this year's race is the tightest in the nine-year history of the Final Vote heading down the stretch.
Youkilis has been an invaluable force for the Red Sox during a first half in which the team has been besieged by injuries.
The first baseman is hitting .297 with 66 runs, 17 homers, 55 RBIs, a .415 on-base percentage and a .999 OPS.
The Red Sox and Reds have formed an alliance to help push the candidacy of both Youkilis (a Cincinnati native and former star the University of Cincinnati) and Reds star Joey Votto, who continues to lead the NL Final Vote ballot.
Even Massachusetts Senator John Kerry got into the spirit of voting for Youkilis, urging all his constituents to do so in an e-mail on Tuesday.
"Yeah, that's a cool thing," Youkilis said of the support from Sen. Kerry. "That speaks volumes how much people love the Red Sox. Red Sox Nation is pretty big, and pretty crazy and wild. For him to do that is a pretty nice gesture. It's a cool thing."
The Red Sox currently have six All-Stars, a list that includes David Ortiz, Jon Lester, Clay Buchholz, Victor Martinez, Dustin Pedroia and Adrian Beltre. They are saving one seat on the plane for Youkilis.
Originally introduced during this year's online balloting for the elected starters, fans can campaign for their favorite player on the Final Vote ballot through MLB.com's All-Star Campaign Manager program, tallying points by getting their friends, family and co-workers to vote through social networking, and competing to be recognized as an "official" Final Vote Campaign Manager for any player they helped support.
Mobile voting is available exclusively on Sprint, Nextel and Boost capable mobile phones and fans can send the word "Vote" to 1122 to receive the 2010 All-Star Game Final Vote Sponsored by Sprint ballot. Message and data rates may apply. In Canada, fans can text "Vote" to 88555. Standard text rates apply.