Factbox-US Congress is on track to be the most polarized ever, data shows

By Jason Lange

WASHINGTON (Reuters) - The current U.S. Congress is on track to be the most polarized ever, according to a running analysis at , a tool widely used by political scientists that sorts lawmakers based on how their voting records overlap with their peers.

The complicated math behind the analysis transforms a lawmaker's entire voting record into one number, with negative numbers for liberals and positive readings for conservatives. The most liberal have the least in common with the most conservative, while moderates from each party have more overlap and are given scores in between.

* U.S. Representative Ralph Norman, a member of the ultraconservative House Freedom Caucus, has a score of 0.85, while U.S. Representative Pramila Jayapal, a Democrat and the leader of the Congressional Progressive Caucus, has a score of -0.65.

* U.S. Senator Joe Manchin, a maverick Democrat, only barely skews liberal with a score of -0.05.

* Since the Republican Party was founded in the 19th Century, the gulf between Republicans and Democrats - measured by the distance between scores in the middle of each party - has mostly varied between 0.5 and 0.85 for every two-year session of Congress. But the gap has hit new records in the last decade.

* Currently, the gap in the House sits at 0.90, beating the 0.89 gaps for lawmakers elected in 2016 and 2018. The current 0.88 gap in the U.S. Senate is also at a record high for that chamber.

(Reporting by Jason Lange; editing by Jonathan Oatis)