As millions of Americans cast their ballots in the midterm elections, the question on everyone's mind is: when will we know the results? The outcome will determine which party, Donald Trump's Republicans or the opposition Democrats, controls Congress, shaping the remainder of Trump's presidency.

Why Results Might Take Time

Once polls close, it could be hours, days, or even weeks before the winners are projected. The complexity arises from the varied rules across states for counting ballots, especially mail-in votes, and the potential for recounts and legal challenges in closely contested races.

The Battle for Congress

Congress consists of two chambers: the House of Representatives and the Senate. To win a majority in the House, a party needs 218 seats. In the Senate, 51 seats secure an outright majority, but if the chamber is split 50-50, the vice-president casts the tie-breaking vote, giving their party control.

Early results after 18:00 EST (23:00 GMT) will come from states like Kentucky and Indiana, which are Republican strongholds, and Vermont, a Democratic safe bet. These won't reveal much about the overall outcome. Instead, analysts will focus on competitive races that indicate how well each party is performing.

Key Senate Races to Watch

Several tight Senate contests in the Eastern Time zone could provide early clues. Ohio's polls close at 19:30 EST (00:30 GMT), and Maine's at 20:00 EST (01:00 GMT). These races might be called early by media outlets if one candidate's lead is insurmountable.

The Cook Political Report identifies six Senate toss-ups: Alaska, Kansas, Iowa, Maine, Ohio, and Texas. All are currently held by Republicans. Democrats would need to win three of these plus five leaning Democratic seats to reach 51 and take control.

In Texas, former teacher James Talarico could become the first Democrat to win a Senate seat there since 1988 if he defeats Ken Paxton, the state attorney general and a close Trump ally. In Michigan, Democrat Abdul El-Sayed, a left-wing outsider, faces Republican Mike Rogers, a Trump ally and former FBI agent. The race was initially a toss-up but shifted to "leans Democrat" just before the vote.

House Races in Focus

The Republican majority in the House is slim: 218 representatives plus one independent who votes with them. Closely watched races include New York's 17th District, Pennsylvania's 8th District, and Virginia's 1st District, according to Cook Political Report.

Timeline of Results

A voter poll will be released at 17:00 EST (22:00 GMT), highlighting the issues most important to voters. Then, at 18:00 EST (23:00 GMT), polls close in Kentucky and Indiana. The focus then shifts to battleground states:

Why Counting Takes Time

Each state administers its own elections with distinct rules for counting and processing votes. Some states, like Florida, process early and mail ballots before election day, while others begin only on election day. Local officials verify, process, and count each vote in a process called canvassing.

Most states require a post-election audit, often a manual count checked against machine totals. Full hand counts are usually reserved for recounts. Every state has rules on who can participate in the canvass, the order of processing, and public access, including how partisan observers can watch and raise challenges.

Close races take longer and may trigger recounts and legal challenges. Mail-in ballots require additional time for envelope processing and signature verification. Over 30 states allow ballots to be processed before election day, but others do not. In California, ballots must be postmarked by election day and can arrive up to seven days later. Alaska's ranked-choice voting could further delay tabulation and lead to legal complications.

Certification and Challenges

After all votes are counted and recounts completed, results are certified first at the local and county levels, then statewide. The governor typically signs the certifications for House and Senate winners, which are sent to Congress.

Results can be challenged. Candidates can request recounts in close races, and some states automatically trigger recounts if the margin is within a certain threshold. Legal contests alleging irregularities can also be filed. Congress has the final say: both chambers can refuse to seat a member or order an investigation.

Outgoing members of Congress leave office on Sunday, 3 January. Because that date falls on a weekend, new members may take office the same day unless Congress passes a law setting a different date.