Which Senate seats are likely to flip on Election Day? Here’s what oddsmakers say

Summer Lin
·3 min read

As Democratic presidential nominee Joe Biden leads President Donald Trump by double digits in national polls, bookmakers are predicting that six Senate seats will flip on Election Day.

As of Monday, Biden has a 10-point lead on Trump nationally, according to USA Today’s average of polling averages from RealClearPolitics and FiveThirtyEight.

Biden is also leading Trump in 10 out of 11 swing states and increased his lead in seven states, including North Carolina, Pennsylvania, Florida and Michigan, according to the publication.

The U.S. Senate is controlled by the GOP, with 53 Republicans and 47 Democrats (including two independents). With 35 seats up for grabs in the Nov. 3 election, 23 of which are currently held by Republicans, Democrats would need to win three or four seats to get a majority (three if Biden wins, four if Trump is reelected, due to the vice president’s role in breaking ties), according to the political website 270toWin.

Because senators tend to vote along party lines and a majority vote is required to pass legislation, the Senate majorities often determine which bills get passed on the chamber floor.

In order to gain a Senate majority, Democrats will likely have to win in Colorado, Maine, Arizona and North Carolina, according to The Washington Post. Cory Gardner of Colorado is likely to be the “most vulnerable” Republican senator, according to the outlet.

Oddsmakers predict that Alabama’s Senate seat will flip to Republican while Colorado, Arizona, Maine, North Carolina and Iowa’s seats is likely flip to the Democrats.

Here are the betting odds for some key Senate races, according to data released Monday by Bookies.us.


Republican challenger Tommy Tuberville has 1/8 odds, meaning that betting $800 will give back $100 in profit. Tuberville is favored to beat incumbent Democrat Doug Jones, who has 9/2 odds.


Betting odds show Arizona’s seat will flip from Republican to Democrat, with Republican incumbent Martha McSally having 7/2 odds and Mark Kelly have 1/6 odds.


Oddsmakers say Democrat John Hickenlooper with 1/7 odds will defeat Republican incumbent Cory Gardner with 4/1 odds.


Democratic challenger Theresa Greenfield is the favorite to win with 4/5 odds, narrowly beating out Republican incumbent Joni Ernst, who has 10/11 odds.


Oddsmakers say Kentucky is likely to remain under Republican control, as incumbent Mitch McConnell with 1/8 odds is heavily favored to beat Democratic challenger Amy McGrath, who has 9/2 odds.


Democratic challenger Sara Gideon is favored to win the election with 4/11 odds, beating out Republican incumbent Susan Collins, who has 2/1 odds.

North Carolina:

Democrat Cal Cunningham has 4/6 odds of winning and is favored to beat Republican incumbent Thom Tillis, who has 11/10 odds.

South Carolina:

Republican incumbent Lindsey Graham is favored to keep his Senate seat with 4/9 odds, likely defeating Democrat Jaime Harrison, who has 13/8 odds.

Those predictions also line up with the odds released by Bookmaker, another betting site. For instance, McSally has +422 odds of winning compared to Kelly with -585 odds. That means wagering $100 would yield $422 for McSally while you’d have to bet $585 in order to win $100 for Kelly, since his win is more likely.

Bookmaker also has Ernst and Greenfield neck-to-neck in Iowa with Greenfield being the slight favorite. Ernst has -114 odds while Greenfield has -106.