Blue Dog Democrats tend to move to the right in election years, which is understandable given that they typically represent swing districts.

And lately no district has swung more than Illinois’ 10th, in the affluent suburbs north of Chicago. Democratic Rep. Brad Schneider is currently serving his second, nonconsecutive term, having defeated Republican Robert J. Dold in 2016.

In 2014, Dold defeated Schneider, who was then in his first term, having beaten Dold in the 2012 election.

In 2017, Schneider was a relatively loyal Democrat, voting with his party on House votes that split a majority of Democrats from a majority of Republicans 88.1 percent of the time, compared to a party average of 96 percent.

But this year, he’s tied with Texas’ Henry Cueller with the second-lowest CQ party unity score among Democrats as of the end of June, 68.5 percent, trailing only Arizona Rep. Kyrsten Sinema.