Democratic candidate for U.S. Senate Doug Jones takes questions from reporters at a fish fry campaign event at Ensley Park, November 18, 2017 in Birmingham, Alabama. Jones has moved ahead in the polls of his Republican opponent Roy Moore, whose campaign has been rocked by multiple allegations of sexual misconduct. (Photo by Drew Angerer/Getty Images)
PHOTO: Drew Angerer/Getty Images
Democratic candidate for U.S. Senate Doug Jones takes questions from reporters at a fish fry campaign event at Ensley Park, November 18, 2017 in Birmingham, Alabama. Jones has moved ahead in the polls of his Republican opponent Roy Moore, whose campaign has been rocked by multiple allegations of sexual misconduct. (Photo by Drew Angerer/Getty Images)
Now playing
00:45
Jones says he was unaware of Obama robocall
BIRMINGHAM, AL - DECEMBER 12: Democratic U.S. Senator elect Doug Jones greets supporters during his election night gathering the Sheraton Hotel on December 12, 2017 in Birmingham, Alabama. Doug Jones defeated his republican challenger Roy Moore to claim Alabama's U.S. Senate seat that was vacated by attorney general Jeff Sessions. (Photo by Justin Sullivan/Getty Images)
PHOTO: Justin Sullivan/Getty Images North America/Getty Images
BIRMINGHAM, AL - DECEMBER 12: Democratic U.S. Senator elect Doug Jones greets supporters during his election night gathering the Sheraton Hotel on December 12, 2017 in Birmingham, Alabama. Doug Jones defeated his republican challenger Roy Moore to claim Alabama's U.S. Senate seat that was vacated by attorney general Jeff Sessions. (Photo by Justin Sullivan/Getty Images)
Now playing
02:00
Doug Jones' victory in Alabama: the key moments
BIRMINGHAM, AL - NOVEMBER 18: Democratic candidate for U.S. Senate Doug Jones takes questions from reporters at a fish fry campaign event at Ensley Park, November 18, 2017 in Birmingham, Alabama. Jones has moved ahead in the polls of his Republican opponent Roy Moore, whose campaign has been rocked by multiple allegations of sexual misconduct. (Photo by Drew Angerer/Getty Images)
PHOTO: Drew Angerer/Getty Images
BIRMINGHAM, AL - NOVEMBER 18: Democratic candidate for U.S. Senate Doug Jones takes questions from reporters at a fish fry campaign event at Ensley Park, November 18, 2017 in Birmingham, Alabama. Jones has moved ahead in the polls of his Republican opponent Roy Moore, whose campaign has been rocked by multiple allegations of sexual misconduct. (Photo by Drew Angerer/Getty Images)
Now playing
02:13
Meet Alabama's new Democratic Senator (2017)
BIRMINGHAM, AL - DECEMBER 12:  Voters wait in line to cast their ballot at a polling station setup in the St Thomas Episcopal Church on December 12, 2017 in Birmingham, Alabama. Alabama voters are casting their ballot for either Republican Roy Moore or his Democratic challenger Doug Jones in a special election to decide who will replace Attorney General Jeff Sessions in the U.S. Senate.  (Joe Raedle/Getty Images)
PHOTO: Joe Raedle/Getty Images
BIRMINGHAM, AL - DECEMBER 12: Voters wait in line to cast their ballot at a polling station setup in the St Thomas Episcopal Church on December 12, 2017 in Birmingham, Alabama. Alabama voters are casting their ballot for either Republican Roy Moore or his Democratic challenger Doug Jones in a special election to decide who will replace Attorney General Jeff Sessions in the U.S. Senate. (Joe Raedle/Getty Images)
Now playing
01:51
Alabama voters deeply divided on racial lines
hillary clinton 12.12
hillary clinton 12.12
Now playing
01:11
Hillary Clinton reacts to Doug Jones' victory
Now playing
01:38
Democratic win changes Senate, impacts Trump
Guest iso 11p special coverage
Guest iso 11p special coverage
Now playing
01:23
Barkley: AL has rednecks and amazing people
Now playing
00:49
Roy Moore: It isn't over
Alabama Senate Race Election Coverage
PHOTO: Pool
Alabama Senate Race Election Coverage
Now playing
01:17
Jones: We have shown the country we can unify
BIRMINGHAM, AL - DECEMBER 12: Democratic U.S. Senator elect Doug Jones greets supporters during his election night gathering the Sheraton Hotel on December 12, 2017 in Birmingham, Alabama. Doug Jones defeated his republican challenger Roy Moore to claim Alabama's U.S. Senate seat that was vacated by attorney general Jeff Sessions. (Photo by Justin Sullivan/Getty Images)
PHOTO: Justin Sullivan/Getty Images
BIRMINGHAM, AL - DECEMBER 12: Democratic U.S. Senator elect Doug Jones greets supporters during his election night gathering the Sheraton Hotel on December 12, 2017 in Birmingham, Alabama. Doug Jones defeated his republican challenger Roy Moore to claim Alabama's U.S. Senate seat that was vacated by attorney general Jeff Sessions. (Photo by Justin Sullivan/Getty Images)
Now playing
01:02
Trump on Jones win: A hard fought victory
Democratic senatorial candidate Doug Jones speaks during a "get out the vote rally," Saturday, Dec. 9, 2017, in Birmingham, Ala. (AP Photo/Brynn Anderson)
PHOTO: Brynn Anderson/AP
Democratic senatorial candidate Doug Jones speaks during a "get out the vote rally," Saturday, Dec. 9, 2017, in Birmingham, Ala. (AP Photo/Brynn Anderson)
Now playing
02:00
CNN Projection: Doug Jones elected to US Senate
Now playing
01:02
Santorum: Voters expect Senate to do their job
Actor and Comedian Keegan-Michael Key sent in his endorsement for Democratic nominee for US Senate Doug Jones which appeared on Jones' Twitter page.
PHOTO: @GDouglasJones/Twitter
Actor and Comedian Keegan-Michael Key sent in his endorsement for Democratic nominee for US Senate Doug Jones which appeared on Jones' Twitter page.
Now playing
01:57
Doug Jones touts celebrity endorsements
PHOTO: CNN
Now playing
04:28
Tapper on closing days of Alabama Senate race
PHOTO: NICHOLAS KAMM/AFP/Getty Images/Scott Olson/Getty Images
Now playing
04:34
Lemon: A day of reckoning in Alabama
FAIRHOPE, AL - DECEMBER 05:  Republican Senatorial candidate Roy Moore speaks during a campaign event at Oak Hollow Farm on December 5, 2017 in Fairhope, Alabama. Mr. Moore is facing off against Democrat Doug Jones in next week's special election for the U.S. Senate.  (Photo by Joe Raedle/Getty Images)
PHOTO: Joe Raedle/Getty Images
FAIRHOPE, AL - DECEMBER 05: Republican Senatorial candidate Roy Moore speaks during a campaign event at Oak Hollow Farm on December 5, 2017 in Fairhope, Alabama. Mr. Moore is facing off against Democrat Doug Jones in next week's special election for the U.S. Senate. (Photo by Joe Raedle/Getty Images)
Now playing
03:16
Alabama voters weigh in on Moore's comments

Story highlights

Special election coverage will begin at 5 p.m. ET on CNN

Polls open at 8 a.m. ET Tuesday and close at 8 p.m ET

(CNN) —  

The hotly contested race between Republican Roy Moore and Democrat Doug Jones will come to a close Tuesday when Alabama voters go to the polls for the special Senate election.

The big story surrounding this race is whether allegations that the 70-year-old Moore pursued sexual relationships with teenage girls – one of whom was 14 at the time – while in his 30s will be enough for Alabama to elect a Democrat to the seat for the first time in 25 years.

Moore, who is also known for being ousted twice as state Supreme Court chief justice, says his accusers are lying. Jones has contrasted the allegations facing Moore with his own history prosecuting two Ku Klux Klan members in the 1963 Birmingham church bombing that killed four African-American girls.

When polls close

Polls open at 8 a.m. ET and close at 8 p.m. ET.

Based on historical patterns in Alabama, nearly 70% of the vote is expected to be reported by 11 p.m. ET.

How to watch

CNN’s special election coverage will begin at 5 p.m. ET on CNN and stream live for subscribers on CNNgo and the CNN mobile apps for iOS and Android.

What are the key counties?

Jefferson County is a big area to watch as it is the largest county in the state and also is home to Birmingham, the largest city in the state. It’s also an area that went for incumbent Sen. Luther Strange in the Republican runoff, which occurred in September.

The suburbs of Shelby County, which neighbors Jefferson County, will also be watched closely due to the high population and the fact that Strange carried it in the runoff.

Etowah County is Moore’s home county and where voters know him best. He did over perform there in the runoff, but not by much: he garnered 57% of the vote there vs. 55% overall in the state.

When will the winner join the Senate?

From the Secretary of State’s office:

Per Alabama state law, results must be certified by January 3 – 22 days from the election.

They are hopeful they will be able to certify the results sometime between December 27 and 29.

Those late December dates, however, are contingent upon all 67 counties meeting the December 22 deadline to report their results. If counties miss that deadline, it will cause problems and possibly a delay in certification.

The Senate is currently expected to adjourn for the year on December 22, after voting on the Republican tax bill and a spending bill to keep the government open.

Should Moore win, it won’t change the vote calculus, which is 52 Republicans and 48 Democrats. A Jones win would mean Republicans only have a 51-49 advantage, and Democrats will be expected to demand he be seated immediately.

Last-minute activity

Over the weekend, Trump recorded a robocall for Moore while former President Barack Obama did the same for Jones. Moore has remained quiet, not participating in any public events since Tuesday, while Jones used the weekend as a final opportunity to barnstorm the state. Jones was joined on the campaign trail by Sen. Cory Booker, who traveled to Alabama to help galvanize African-American and other Democratic voters to go to the polls.

CNN’s Jennifer Agiesta and Adam Levy contributed to this story.