WASHINGTON Texas Sen. Ted Cruz is raising the possibility that Republicans would decline to fill the Supreme Court’s vacancy if Democrat Hillary Clinton is elected president.

Cruz is the second Republican to suggest that the GOP will simply block any Democratic nominee to replace the late Justice Antonin Scalia, who died in February. Arizona Sen. John McCain made a similar assertion earlier this month.

Speaking to reporters while campaigning for Republicans on Wednesday, Cruz was asked about Supreme Court vacancies.

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“There will be plenty of time for debate on that issue, there is long historical precedent for a Supreme Court with fewer justices, just recently Justice (Stephen) Breyer observed that the vacancy is not impacting the ability of the court to do its job, that’s a debate that we are going to have,” Cruz said, in a quote later provided by his office.

Breyer said this week on MSNBC’s “Morning Joe” program that “the mechanics works about the same” with a 4-4 split on the court as they do with the normal 5-4.

President Obama nominated Judge Merrick Garland for Scalia’s seat in March, but Senate Republicans, led by Majority Leader Mitch McConnell, declined to even hold hearings as they insisted the voters choosing the next president would have the final say on the vacancy. Cruz said the best way to ensure conservatives are nominated to the court is to put a Republican in the White House and keep the GOP in control of the Senate.

“For those of us who care passionately about the Constitution and Bill of Rights, who care about free speech and religious liberty and the 2nd Amendment, the best way to protect those rights is to win on Election Day so that we see strong conservatives nominated to the court, and maintain a Republican majority in the Senate to confirm those strong conservatives,” Cruz said.

Outgoing Senate Democratic Leader Harry Reid used Cruz’s comments in a fundraising email Wednesday night.

“Ted Cruz and John McCain may have given away the Republican game plan on the Supreme Court,” Reid wrote in the email sent by the Progressive Change Campaign Committee. “And we need to treat it like the constitutional crisis it will be if Democrats don’t take back the Senate majority.”

Cruz, who lost the presidential primary to Donald Trump, endorsed the nominee recently after telling Republicans to vote their conscience at this summer’s Republican convention, a move that drew condemnation from some in the GOP.

The size of the court is set by federal law and has changed over the years, but has been nine justices for most of its existence. Initially, there were six justices. The court reached its highest number, 10, during the Civil War. There has been a nine-justice court since 1869.

When vacancies arise, they usually are filled within months, if not weeks. But there have twice been stretches of more than two years where the court was one justice short. Another six vacancies lasted more than a year. The most recent of those was in 1969 and 1970, when Justice Abe Fortas resigned and the Senate rejected two of President Richard Nixon’s nominees before confirming Justice Harry Blackmun.

McCain’s comments came in an interview on a Philadelphia radio station to promote the candidacy of Sen. Pat Toomey, R-Pa., a vulnerable Senate GOP incumbent.

“I promise you that we will be united against any Supreme Court nominee that Hillary Clinton, if she were president, would put up,” McCain said.

He added, “This is the strongest argument I can make to return Pat Toomey, so we can make sure there are not three places on the United States Supreme Court that will change this country for decades.”

An aide to McCain, R-Ariz., later clarified that he will examine the record of anyone nominated for the high court and vote for or against that person based on their qualifications.

After McCain’s comments, Senate Judiciary Committee Chairman Charles Grassley said Republicans “can’t just simply stonewall” nominees to the Supreme Court even if the president making the choice is Democrat Hillary Clinton.