Over the weekend, moderate GOP Rep. Ryan Costello (PA-06) confirmed that he wouldn't run for reelection, reversing course just days after filing petitions to put his name on the ballot. The move deprives Republicans of a well-liked incumbent with $1.3 million in the bank in a suburban Philadelphia district and puts Democrat Chrissy Houlahan in the driver's seat to take over a very favorably redrawn seat.

Costello was probably the biggest loser in Pennsylvania's new court-ordered map. The new 6th CD unites all of Chester County, a bastion of formerly GOP suburban professionals who revolted against Trump in 2016, with the heavily Latino, Democratic city of Reading. The result is a district Hillary Clinton carried 53 percent to 43 percent, up from 48 percent to 47 percent under the old lines.

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Costello had suggested impeaching the judges who imposed the map. Ultimately, he bowed out. A second Republican, attorney Greg McCauley, filed for the May 15 primary and had been challenging Costello from the right. The former Wendy's restaurant franchise owner is now the likely GOP nominee, but his positions on guns and immigration put him to the right of the district and he begins with a massive resource disadvantage.

Houlahan, an Air Force veteran who became an executive for the AND1 athletic wear brand, ended 2017 with $950,000 and is frequently billed as one of her party's top recruits. Had Costello stayed in the race, AND1's outsourcing and labor conditions in Asia could have become a line of attack that kept him in the fight. Without him, however, the race moves from the Toss Up column to the Likely Democratic column.

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