Pennsylvania’s Senate race between Sen. Bob Casey (D-PA) and Republican Senate nominee Dave McCormick was switched to being a “toss up,” according to a recent report.

The Cook Political Report moved the race between Casey and McCormick to the “toss up” column. Other races in the column consisted of the Wisconsin Senate race between Sen. Tammy Baldwin (D-WI) and Republican U.S. Senate candidate Eric Hovde, and the Ohio Senate race between Sen. Sherrod Brown (D-OH) and Republican U.S. Senate candidate Bernie Moreno.

The report noted that the race between Casey and McCormick had been moved to a “toss up” as McCormick was “shoring up the GOP base and making gains in the western part of the state,” according to Fox News:

Cook cited McCormick “shoring up the GOP base and making gains in the western part of the state,” as part of its justification. It also noted that while Casey has a several point advantage over his opponent in public polls, the race is reportedly within the margin off error in both Democratic and Republican internal surveys.

As Breitbart News’s Nick Gilbertson previously reported, a polling memorandum from the National Republican Senatorial Committee (NRSC) found that Republican Senate candidates were leading in states such as Montana, Ohio, and Wisconsin.

The memo also found that Republican Senate candidates in Pennsylvania and Michigan were “neck and neck” with their Democrat opponents.