(CNN) Democratic Sen. Joe Manchin leads his Republican challenger Patrick Morrisey in the West Virginia Senate race, according to a Monmouth University poll released Wednesday.

Manchin represents a top GOP target this cycle, with West Virginia being one of five contests where Democratic senators are seeking re-election in a state President Donald Trump carried by double-digits in 2016.

The survey shows Manchin with a 48% to 39% advantage over Morrisey, the state's attorney general. Another 4% back ex-con coal baron Don Blankenship, who lost the GOP primary in May and is now trying to run as the Constitution Party candidate. His bid is in question, however, because of West Virginia's "sore loser" law.

Manchin holds a 49% to 42% lead over Morrisey without Blankenship in the race.

The incumbent Democrat maintains a similar lead over Morrisey when Monmouth uses different models to reflect historical midterm turnout and one with a Democratic surge.

Read More