Republicans suffer setbacks in US state polls

US President Donald Trump's Republican Party has suffered setbacks in two states, losing the governorship of Kentucky and the legislature in Virginia a year away from the presidential election.

Kentucky Governor Matt Bevin lost re-election very narrowly on Tuesday by less than half-a-per cent or about 5,100 votes, but the loss is significant because Trump had won Kentucky in the 2016 presidential election with a 30 per cent lead.

The defeat of Bevin, for whom Trump campaigned, was tempered by the victory of Republican candidates in five other state-wide offices like secretary of state and attorney general, though with smaller margins compared to Trump's showing an erosion of Republican support.

In Virginia both the upper and lower chambers of the state legislature flipped to the Democrats giving them full control of the government for the first time in many decades. Democrat Governor Ralph Northam was already in office.

The Republicans kept the governorship of Mississippi with Lieutenant Governor Tate Reeves winning with a six per cent lead, much lower than Trump's 17.8 per cent.

New Jersey was a silver lining for Republicans. Complete results were not in by early Wednesday morning but NJ.com reported that the Republicans were set to gain at least four seats. That won't be enough to switch control of the legislature now held by Democrats with a 28-seat margin in the 80-member Assembly.

With the presidential election just under a year away, Tuesday's elections showed that Trump's margins of victory in 2016 had been shaved significantly even when his party candidates won.

Looking ahead, according to RealClearPolitics, the authoritative aggregator of polls, as of now all the five front-runners for the Democratic Party nomination - Joe Biden, Elizabeth Warren, Bernie Sanders, Kamala Harris and Pete Buttigieg - lead Trump by between 4.5 and 10 per cent.

Trump in a tweet claimed credit for the five Republican wins in Kentucky and the governorship in Mississippi. He even claimed that he had boosted the votes for Bevin 15 points for whom he had campaigned. He added, "Fake News will blame Trump for Bevin's loss."

Democrat Andy Beshar, who defeated Bevin, concentrated on local issues in his campaign and avoided making it a referendum on impeachment.

Bevin has not conceded defeat and is expected to contest the results because of the slender margin.

In Virginia, the Republican candidates for the state legislature avoided involving Trump in their campaigns unsure of his effect on the electorate.

Elections were also held in some other states on Tuesday, but they were referendums or at local level or for individual legislature seats.