Senator John Cornyn of Texas tells National Review Online that the Obama administration’s refusal to appoint an independent prosecutor to investigate a series of intelligence leaks to the New York Times is a “cover up.”

“It’s all politics, all the time, at the Department of Justice,” Cornyn says. “Now that they’re in cover-up mode, they’re hiring Obama-campaign volunteers to look into the leaks.”

Earlier this week, Attorney General Eric Holder tapped a pair of his deputies, two federal prosecutors, to investigate whether any Obama-administration official shared highly classified military intelligence with a Times reporter.

Cornyn, a member of the Senate Judiciary Committee, says the president’s decision not to seek a special prosecutor is an “astonishing” failure of leadership and a clear sign of “desperation” on Pennsylvania Avenue.

On Tuesday, a few hours after calling on Holder to resign, Cornyn, along with Senator John McCain of Arizona, attempted to introduce legislation that calls for an outside counsel to investigate the leaks. Senate Majority Leader Harry Reid, a Democrat, promptly blocked the resolution.

Cornyn, however, is undeterred by Reid’s maneuver. He’ll push similar legislation to the floor in the coming days — and he is willing, he says, if necessary, to hold up the Senate’s business to get a vote. “There will be steps taken to try to force a vote,” he says. “It’s not easy, but sometimes you have to hold up other things people want.”

In the near term, Cornyn says, he plans to release a letter signed by a “significant number of senators” calling for a special counsel as a precursor to another vote.