Is a "blue wave" coming in November?

Michael Li thinks so. But that doesn't necessarily mean there'll be a new Democratic majority in the House.

His prediction has nothing to do with voter engagement and everything to do with gerrymandering.

Li co-authored "Extreme Gerrymandering & the 2018 Midterm," a report released Monday by the Brennan Center for Justice. Li, senior counsel at the non-partisan public policy and law institute, said that Democratic turnout may very well be high. The release of the report comes as the Supreme Court will hear evidence this week that Democrats try to game the political system with the same zeal employed by Republicans.

The Brennan Center report focused on the challenges faced by Democrats because of Republican control in many states post-2010 and because 2018 appears to be a good year for Democrats electorally.

This year, voters will be contending with congressional districts that were drawn in the aftermath the 2010 Tea Party wave, when Republicans in several states held the reins for redistricting. Li's analysis found that these maps would likely hinder the 24-seat gain Democrats would need for a majority.

The authors call their new study a "stark warning to both courts and the public."

"What looks to be one of the most important recent midterm elections may turn out, in fact, to show how effectively extreme gerrymandering distorts American democracy and blunts the public’s voice," the report reads.

The report analyzed each state for "responsiveness" — essentially, whether the political party that wins more votes also wins more seats — by looking at the results from the 2012, 2014 and 2016 elections to generate seats-to-votes curves.

The worst offenders: Michigan, North Carolina, Ohio and Texas. In each of these states, the Democratic Party could "increase its vote share by 10 or even 20% without gaining a single extra seat," the report said.

Nationally, Democrats would need to win by an 11-point margin to retake the House, Li said. That threshold hasn't been reached since 1982, when Democrats won the House by 12 points amid Ronald Reagan's election to the presidency.

Still, the report doesn't account for a number of factors, such as incumbency, third-party candidates, shifting demographics, turnout and scandalous behavior. And the number of retirements in the House could make it easier for Democrats to win seats.

That still may not be enough to shift control of Congress.

"We want the report to be a reality check," Li said.