Doug Jones's victory in Alabama gives Democrats sudden hope of taking control of Congress in 2018

There are going to be tough fights in several battleground states next year

Mr Jones acknowledges supporters at the election night party in Birmingham, Alabama (Reuters)

Following the stunning election of Democrat Doug Jones in the Alabama Senate race, it’s even more likely to be a dramatic and vicious battle for control of the US Senate and House of Representatives next year.

Democrats now only need a net gain of two seats to win a majority in the 100-member upper chamber. Meanwhile, the party needs a net gain of 24 to retake control of the 435-member House.

Planned resignations and announced retirements are hitting Republicans harder. Of the 18 House members who have announced that they will not seek re-election in 2018, more than two thirds are Republican. Additionally, both House congressmen who will retire over the next few months are also part of the GOP. Special elections to fill those seats have not yet been announced.

As moderate Republican members get ready to depart Congress, conservatives want stronger allies in their seats, while Democrats see opportunities to turn them blue.

The campaign committees for both parties are looking at the 23 Republicans defending districts that Hillary Clinton won in 2016, and the 12 held by Democrats in districts that President Donald Trump won as vulnerable seats to flip.

In regard to the Senate races, several are expected to be very competitive. Mr Jones was able to pull off an upset in a deeply conservative state – strengthening Democratic momentum going into 2018 – but many party members still face tough re-election contests next year.

Several incumbents, such as Democratic senators Joe Manchin of West Virginia and Heidi Heitkamp of North Dakota, are running for re-election in states that overwhelmingly went to Mr Trump last year.

Texas Republican Senator Ted Cruz is also up for re-election. While many wouldn’t consider the Lone Star State a political battleground between Democrats and Republicans – the state has been a reliable Republican stronghold for the past few decades – a former Obama administration official sent a warning to Mr Cruz in the wake of Roy Moore’s defeat in Alabama.

“Be afraid, @tedcruz. Be very afraid” wrote former Secretary of Housing and Urban Development Julian Castro on Twitter. Mr Castro served as the mayor of San Antonio prior to joining the Obama administration.

Here are some possible big battlegrounds in 2018.

Arizona

Republican Senator Jeff Flake has announced he will not run for re-election in 2018, likely upending the race for his seat by doing so. It’s looking to be a tough primary fight for Republicans in the Republican-leaning state. The winner of the could face Democratic Representative Kyrsten Sinema, who is considered the Democratic Senate primary front-runner.

Florida

In 2016, President Donald Trump won 49 per cent of the vote in Florida while his Democratic opponent Hillary Clinton won 48 per cent. This fact alone could make Democratic Senator Bill Nelson’s re-election bid his toughest yet.

Indiana

The state handily went to Mr Trump in 2016 and is the home of Vice President Mike Pence. The Democratic incumbent, Senator Joe Donnelly, won his underdog race for the Senate in 2012 partially as a result of blunders by his Republican opponent. He may not get so lucky in 2018.

Missouri

Missouri is another state that strongly preferred Mr Trump over Ms Clinton last year, with 57 per cent of the vote going to the Republican candidate. Mr Trump has already targeted the re-election bid of Democratic Senator Claire McCaskill on Twitter, predicting a Republican candidate will take her seat in 2018 because she has opposed his proposed tax cuts.

Nevada

Republican Senator Dean Heller won his last election by just 1 point, and his state has become more Democratic since then. Nevada was also of the few battleground states Ms Clinton won in 2016, when Nevada voters also elected the US’s first Latina senator, Catherine Cortez Masto.

Minnesota

With the resignation of Senator Al Franken, Minnesota politics could get wild next year. The state legislature is controlled by Republicans, while the biggest statewide elected offices – governor, attorney general, and both US Senate seats – are controlled by Democrats. It has not yet been announced when the special election will be held to fill Mr Franken’s Senate seat. Additionally, Democratic Senator Amy Klobuchar is running for re-election in 2018 for a third term.