President Donald Trump weighed in again on metro Atlanta’s 6th district race, on the final day of a special election that has become the nation’s most expensive congressional race in history.

Trump, who has been an active supporter of Republican Karen Handel, tweeted out his support of the candidate:

Later on Monday, Trump sent two additional tweets:

Voters go to the polls on Tuesday to choose between Handel and Democrat Jon Ossoff in the race to replace Tom Price, now the president’s secretary for the U.S. Department of Health and Human Services.

More than 133,000 early and mail-in votes have already been cast during advance and mail-in voting. The district includes portions of DeKalb, Cobb and Fulton counties.

GALLERY: Karen Handel campaign rally before election day

The race has attracted national donors and attention, and has become a virtual must-win for both parties.

The seat has been in GOP hands since 1978, having been held by such Republican stalwarts as Newt Gingrich and Johnny Isakson. Price himself was easily reelected several times, but Trump himself carried the district over Hillary Clinton by less than two percentage points last November, fueling Democratic hopes that they can flip the district.

There have already been two special congressional elections since President Trump took office, and both were won by Republicans. Democrats hope a victory tomorrow will fuel momentum for the 2018 midterm elections.

Handel has featured rallies and fundraisers hosted by Trump, Vice President Mike Pence, U.S. House Speaker Paul Ryan, and Price himself.

Ossoff has been endorsed by his former boss, U.S. Rep. Hank Johnson, as well as U.S. Rep. John Lewis and other locally and nationally prominent Democrats.

On April 18, both candidates emerged from a field of 18 to qualify for Tuesday’s runoff. Ossoff finished with 48 percent of the vote, falling just short of winning the special election outright, compared to Handel’s 20 percent.

Voter turnout on April 18 was 44 percent, according to the Georgia Secretary of State. A total of 193,981 ballots were cast in that election.

FULL COVERAGE | Race to replace Tom Price in the 6th district

A recent, exclusive 11Alive poll conducted by Survey USA showed both candidates in a dead heat, each with 47% of the vote, with 6% undecided.

PHOTOS: Exclusive new 11Alive poll in the 6th district