You can read the logic on Liberty Unyielding in an article by its staff.
They point out that Republicans received of the national vote for members of the House of Representatives.
Republicans got four million more popular votes than Democrats in House races, so it is only natural than they won control of the House by a narrow margin. Republicans got 74,826,851 votes, compared to only 70,836,229 votes for the Democrats. As law professor Eugene Volokh points out, Democrats got only 48.64% of the vote cast for the two parties, compared to 51.36% for the Republicans. Republicans got only 50.57% of the seats in the House, so they actually received a lower percentage of seats than popular votes.
Further, that gerrymandering by Republicans in states like North Carolina was balanced out by what Democrats did in Illinois and other jurisdictions in which Democrats held control.
In Illinois, thanks to gerrymandering, the Democrats won 14 of Illinois’ 17 House seats, despite getting only 52.78% of the vote. Republicans received only 18% of the House seats in Illinois, despite getting 46.97% of the vote. Illinois is one of several states where maps were more skewed in favor of Democrats than maps were skewed in favor of Republicans in North Carolina
