Rob Portman of Ohio, Kelly Ayotte of New Hampshire, Ron Johnson of Wisconsin and Pat Toomey of Pennsylvania – all representing states President Obama won in 2012 and among the incumbents most-targeted by Democrats – said the nomination should wait until 2017.

Republicans backing McConnell’s decision may have calculated that opposition to Obama and his potential nominee will excite their base more than it will motivate their Democratic opponents, and that the issue of a Supreme Court seat will not necessarily be the biggest fault line in the election come November.

“I believe the best thing for the country is to trust the American people to weigh in on who should make a lifetime appointment that could reshape the Supreme Court for generations,” Portman said in a statement Monday.

But Democrats quickly jumped on that stance. Both of Portman’s potential opponents in the race – former Ohio Gov. Ted Strickland and Cincinnati City Councilman P.G. Sittenfeld – criticized him for the decision. Strickland said Portman “abandoned his constitutional duties” by arguing to hold off on a nomination, and that he is “shirking his responsibilities to our nation.”