Midterm elections live updates: Judge orders DOJ to halt threats to election workers

The majorities of both houses of Congress are in play as voters weigh a midterm check on unified control of government in Washington.

Republicans hold slim majorities in both the House and Senate and are rallying to preserve them with just days until Election Day. Democrats on the other hand are trying to make inroads into some traditionally red areas in hopes of picking up crucial seats.

Here's a look at the math around the balance of power.

-ABC News' John Parkinson

Former President Barack Obama will headline a rally in Atlanta, Georgia, on Wednesday alongside incumbent Democratic Sen. Jon Ossoff and Democratic nominee for governor Keisha Lance Bottoms.

The event comes a few days after Obama rallied for Democratic candidates in Michigan and Ohio, and as early in-person voting continues in Georgia. President Donald Trump rallied in Georgia on Saturday.

More than two million Georgians have voted early in person, in record turnout, according to the office of Georgia Secretary of State Brad Raffensperger.

-ABC News' Halle Troadec and Oren Oppenheim

President Donald Trump heads to Chillicothe, Ohio, on Wednesday to rally with candidates, marking his third stop in the state since Labor Day as Republicans and Democrats continue to vie in increasingly acrimonious races for governor, Senate and House.

The visit comes as the Ohio governor's race continues to draw attention following the release of an ad by Republican candidate Vivek Ramaswamy featuring the estranged mother of Democratic candidate Amy Acton. Trump has praised the ad and indicated he believes Ramaswamy should keep it running despite bipartisan backlash.

Ohio is also home to a closely watched Senate race, in which Republican Sen. Jon Husted is facing a tough reelection bid against former Democratic Sen. Sherrod Brown. Trump has frequently brought up Husted at other rallies, sometimes commenting on his appearance.

Several House races in the state are also competitive, including in Ohio's 7th Congressional District. Embattled Republican Rep. Max Miller is seeking reelection while denying domestic abuse allegations made by his ex-wife, the daughter of Ohio Republican Sen. Bernie Moreno.

-ABC News' Oren Oppenheim

Republican Sen. Lisa Murkowski endorsed Democratic candidate Jonathon S. Kreiss-Tomkins in the Alaska governor's race, his campaign announced Tuesday.

"Our future is too important to be hamstrung by partisan divisions," Murkowski said in a statement. "Alaska needs a serious conversation about our fiscal future, as well as a focus on the cost of energy and growing our economy. I believe Jonathan is committed to working toward solutions that serve all Alaskans, regardless of party."

Murkowski has a history of opposing President Donald Trump and bucking her party.

Trump on Saturday called her the "Republicans' Worst Senator" and "a DISGRACE to Alaska and our Country" over her opposition to the Justice Department's lawsuit seeking to block the certification of the Alaska Senate race if Republican incumbent Sen. Dan Sullivan loses.

-ABC News' Emily Chang