The Democrats now have more than a 50 per cent chance of retaking the House of Representatives in November’s midterms, according to one of the nation’s most respected political analysts.

Larry Sabato, Professor of Politics at the University of Virginia and the man who oversees the politics department’s celebrated “Crystal Ball”, has for the first time estimated the Democrats have a better than 50 per cent chance of getting the 218 seats required to control the congress’s lower chamber. Doing so could leave Donald Trump vulnerable to a possible impeachment attempt.

The House is where any legal effort to try and impeach Mr Trump would begin. While the Democratic politicians who currently lead the party in the House, such as minority leader Nancy Pelosi, think seeking the president’s impeachment could further polarise the country and damage the Democrats’ chances in the 2020 presidential election, others support such a move.

It is also unclear whether the 78-year-old Ms Pelosi would lead the Democrats in the House, if they were to take control. There are many in the party who support fresh leadership. A new Democratic Speaker may decide to pursue a case against Mr Trump.

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“[For] most of this election cycle the generic ballot has shown a consistent Democratic lead that suggests a very competitive battle for the majority,” wrote Kyle Kondik, managing editor of Mr Sabato’s Crystal Ball.

“A high number of open seats – the highest number of any postwar election save 1992 – give Democrats many more targets than the GOP.”