Sen. John McCain on Wednesday announced that he would oppose the nomination of Elena Kagan to the Supreme Court, becoming the latest Republican to formally come out against the solicitor general’s bid to become only the fourth female justice.

In an op-ed scheduled to be printed in Thursday’s USA Today, the Arizona Republican argues that he has always sought to determine whether nominees to the Supreme Court have “‘integrity, character, legal competence and ability, experience, and philosophy and judicial temperament.’ On that test, Elena Kagan fails.”

McCain’s decision largely turns on the fact that Kagan limited military recruiters’ access to the Harvard Law School campus during her tenure as dean. Harvard, like other universities, has an anti-discrimination policy that recruiters must sign. But because of the military’s “don’t ask, don’t tell” policy banning openly gay service members, their recruiters were barred from using certain school resources.

McCain joins Senate Minority Leader Mitch McConnell (Ky.), Republican Conference Vice Chairwoman Lisa Murkowski (Alaska), and Sens. Orrin Hatch (Utah) and James Inhofe (Okla.) in opposing Kagan.