Here’s an article about the lawsuit. A bit of data from the filing on the claim:

The groups suing Coffman also estimate that as many as 26,931 voters were purged from the rolls between July 31 and Oct. 31 — within 90 days of the general and primary election.

That’s based on a comparison of the state’s voter registration database on Aug. 15 and on Oct. 13, which showed that the later list was missing 14,089 names shown on the earlier list. Of those, 1,892 were listed as removed because they had died, were convicted of a felony or had asked for their names to be removed, which is allowed under federal law. The others were removed for other reasons not allowed under federal law, the suit claims.

According to the suit, Jonathan Nagler, an expert on voter registration at the New York University, extrapolated based on that information to reach the estimate of 26,931 voters who were wrongly removed for reasons other than the three exceptions.

That’s right — political scientist Jonathan Nagler conducted the analysis behind this lawsuit.