Democrats set to gain control of House in US mid-term elections but Republicans retain Senate

The Republican party has retained control of the Senate for another two years in the US mid-term elections but Democrats look set to take the House of Representatives.

Democrats have won at least 12 of the roughly two dozen seats they need to claim House control but fell short in a closely watched race in Kentucky as they fought to win control of the chamber.

Republicans seized victory in Indiana’s high-profile Senate contest, defeating Democratic incumbent Joe Donnelly and making the Democrats’ narrow path to a Senate majority ever slimmer.

Meanwhile former presidential hopeful Republican Senator Ted Cruz fended off rising-star Democrat Beto O'Rourke to win re-election in a much-watched Texas race.

In what is being seen as a referendum on Donald Trump's leadership, voters are deciding whether Republicans will continue to control both the House of Representatives and the Senate.

If Democrats can take either chamber it will signal a difficult two years ahead for Mr Trump as his opponents seek to block all new legislature.

Democrats seized early victories in contested House races in Florida and also in Virginia, where political newcomer Jennifer Wexton defeated two-term Republican Barbara Comstock.

As polls began closing, former presidential hopeful Vermont independent Senator Bernie Sanders was easily re-elected for his third term in the Senate.

Democrats have pinned their election hopes on women and minority voters while Republicans aimed to retain majorities by preserving support among the bloc of voters who propelled Trump to the White House in 2016.

While Mr Trump is not on the ballot, attitudes toward the polarising leader influenced the decisions of more than 6 in 10 voters, according to a survey by the Associated Press.

Nearly 40 percent of voters cast their ballots to express opposition to the president, according to AP VoteCast, a national survey of the electorate, while about 25 percent said they voted to express support for Trump.

Initial vote counts were too tight to call a pivotal race in Indiana, where Republicans hoped to oust moderate Senator Joe Donnelly and offset possible Democratic gains elsewhere.

Vermont independent Senator Bernie Sanders was easily re-elected, Credit: AP

Democrats' longshot prospects for capturing a Senate majority were pinned on expectations that their supporters, roused by revulsion toward Trump, would surge to the polls.

Fueling their intensity has been Trump's anti-immigration rhetoric and policies, his efforts to dismantle health care protections enacted under President Barack Obama and the #MeToo movement's fury over sexual harassment.

Mr Trump has sought to distance himself from any potential blame if Republicans lose control of the House. Credit: AP

WHO NEEDS WHAT TO WIN

  • In the House of Representatives, where every seat is up for grabs, Republicans currently hold a 235-193 majority. Democrats need a net gain of 23 seats to take control.

  • In the Senate, 35 of the 100 seats are being contested. Republicans hold a narrow 51-49 seat advantage but 10 of the 35 seats being voted on involve Democratic incumbents in states Trump won in 2016.