WASHINGTON (Nexstar) – Congressional races across the country will decide the balance of power in both the Senate and the House of Representatives.

However, officials say voters may not find out who the winner is in key races on election night or which party will win control of Congress — noting the delay is normal and necessary to ensure all votes are carefully counted.

Former President Donald Trump cast his ballot in Florida and made one more pitch for voters to support Republican candidates.

“We have to fight crime, we have to fight to keep our taxes low and you have to do something about the border,” Trump said.

On Monday night, President Joe Biden said voters have plenty of reasons to keep Democrats in control of Congress.

“We’ve created 10 million new jobs, 3.75% unemployment,” Biden explained.

The president also touted the legislation his party has successfully passed including a pandemic relief package and historic investments in infrastructure and fighting climate change.

“But for all the progress, we know a lot of families are still struggling. That’s why, with the help of Congress, I signed into law the Inflation Reduction Act,” Biden said.

Additionally, Democrats expect protecting access to abortion to motivate their supporters.

Casey Burgat, legislative affairs program director at George Washington University, says the election results are likely to be extremely close.

“One, two percentage points are going to be the huge difference between literally owning majority status in either chamber and not,” Burgat said.

Republicans need one additional Senate seat to gain control of that chamber, which could happen if Democrats lose in Nevada, Arizona or Georgia.

But Republicans will also need to hold onto seats in Pennsylvania, Ohio and Wisconsin.

The reasons voters could see some of these races drag on for days, or even weeks, is because some are already being contested in court. Additionally, in Georgia, if one candidate doesn’t get at least 50% of the vote that will head to a runoff.