There’s a battle for power in Congress - with Democrats pushing to retake the Senate.

Remember the blue wave? It swept across the House of Representatives two years ago, washing the gavel away from the GOP, and into the hands of Nancy Pelosi and the Democrats. However, that blue wave hit a big red floodwall in the U.S. Senate.

Mitch McConnell tightly controls the reigns in the upper chamber with Republicans having a 53 seat majority.  However, two years ago, the GOP only had to defend a handful of seats in the midterm election. This year, the numbers play out differently.

“This is a big election with big stakes,” says McConnell.

Of the 35 seats up for grabs in this election, 23 are currently held by Republicans. 

In Arizona, incumbent Martha McSally was appointed, not elected to her seat. McSally replaced the late Sen. John McCain, but is facing a stiff challenge from retired astronaut Mark Kelly.

Polls suggest first-term GOP incumbents Cory Gardner, of Colorado, Joni Ernst, of Iowa, and Thom Tillis, of North Carolina, could be in trouble. Even long-time GOP Senate stalwarts like David Purdue, of Georgia, Susan Collins, of Maine, and Lindsey Graham, of South Carolina are no lock to retain their seats.

“I think the contest in South Carolina has taken on something of a national profile,” says Graham.

On the Democratic side, recent polling suggests only Alabama Sen. Doug Jones figures to face an uphill climb to retain his Senate seat, although Michigan's Gary Peters could be in for a close race. 

Ultimately, Democrats need to flip four seats to take control of the Senate if President Donald Trump wins reelection, and just three if Joe Biden becomes the president-elect. 

In the House, the Democrats hold the majority with 232 seats. Republicans need a net gain of 17 to seize control.

Key races include a pair on Long Island - Shirley Congressman Lee Zeldin trying to hold on against Democrat Nancy Goroff, and Republican Andrew Garbarino and Democrat Jackie Gordon vying to replace the retiring Peter King.

As the presidential race continues to be the focus this election season, remember that the party that controls the dual chambers of the legislative branch will help shape the future of the COVID-19 response, the courts, and your tax bill.