President Barack Obama embraces Congresswoman Gabrielle Giffords before delivering his speech at the 2012 State of the Union. (Pete Souza/Wikimedia Commons)

The special election marks a day of dual significance, one rooted in Giffords' legacy and another that sets the stage for a greater political battleground. The outcome is expected to help foreshadow how independent voters will cast their ballots in the upcoming Presidential election.

Roughly a year ago, Giffords was the victim of a shooting rampage outside of a local Tuscon supermarket.  As Neon Tommy previously reported, Giffords suffered a gunshot through the head at point-blank range during a community meeting.  Six were killed and a dozen others injured.

For Giffords, Tuesday's race ends a big chapter of her political career.  

“This is a little about closure,” said Giffords' husband Mark Kelly. “This closure on Gabby’s career in Congress . . . I really, truly believe that this is this coming Tuesday.”

Barber, a former aide to Giffords who was injured in the 2011 shooting, seeks to earn his place in Congress and continue the legacy Giffords left behind when she resigned in January to focus on her recovery.  He goes up against tea-party-backed Republican Jesse Kelly, who narrowly lost to Giffords in a 2010 election.

On Saturday, Giffords attended a get-out-the-vote rally to thank her supporters and campaign for Barber.  CBS News reports that Republicans have used Giffords' ties to Barber as a platform to gauge voter interest on President Obama.  Arizona's 8th District, historically a battleground region, has registered Republicans outnumbering Democrats by more than 25,000 people and should offer insight into how swing districts will vote in the fall.  

If Kelly wins, the Republican party could use it as a way to lay claim to a political momentum that swings in their favor, thanks to a recent win in Wisconsin's gubernatorial election.  

Outside groups have taken keen interest in the race, outspending even the candidates.  Both Democratic and Republican groups have plowed $2.5 million into the special election, trumping Barber's $1.2 million and Kelly's $756,000 contributions.  

The Democratic Congressional Campaign Committee has spent $460,000 and the party's House Majority PAC checks in at $700,000 in donations.  Democrats seek to paint Kelly as an extremist, calling out the candidate for his notion of phasing out Social Security.  Currently the House Majority PAC is running an ad that highlights Kelly's past comments, including some that cast a negative light on Giffords.

One reason for the increased Democratic interest is the larger implications the Arizona election has for the party as a whole.  According to the Associated Press, the seat is critical for Democrats who look to regain control of the House.  The party needs 25 seats come November for majority control.

In comparison, the National Republican Congressional Committee has contributed in excess of $878,000 to Kelly's campaign.  The party has used Barber's standing as a way to open up dialogue on Obama's controversial policies, including health care reform.

Currently, polls suggest a neck-and-neck race, with Barber leading 53 percent to Kelly's 41 percent.  Over half of the voters in the election have already cast early mail-in ballots, which decreases the impact of Giffords' influence and momentum for Barber.

Following the special election, both candidates will turn around and campaign for a full term seat in next year's Congress.

For more of Neon Tommy's 2012 Election coverage click here; for more of Neon Tommy's coverage on Gabrielle Giffords look here.

Reach Supervising Executive Producer Amanda Martinez here.