Two years ago, Senator Rand Paul had a shot at winning the Republican presidential nomination in 2016, especially as he seemed interested in moving closer to the center on a number of issues. His chances have diminished significantly since then as the libertarian moment in American politics has passed. As I wrote yesterday, his attempt to torpedo the renewal of the Patriot Act shows that he has fallen back on the libertarian base he inherited from his father, and that the attempt to become the leader of his party as opposed to championing a faction of it has been abandoned. But any lingering doubts about his viability as a candidate evaporated in one moment yesterday on the floor of the Senate when he claimed those who support the legislation he’s trying to kill actually “secretly want there to be an attack on the United States so they can blame it on me.” If anyone still thought Paul was presidential timber, rather than just a housetrained version of his more extreme father, that line is a timely reminder that they are mistaken.

While the Kentucky senator partially walked that statement back this morning when he admitted on Fox News that it was “hyperbole,” he neither apologized nor completely retracted it. Instead, he continued to insist that supporters of the PATRIOT Act and the House version of the renewal attempt were spreading fear. As with some of the botched interviews he gave to the press after he declared his candidacy this year, this line illustrated the brittle nature of his personality. This is a man willing to publicly accuse his opponents of just about anything, up to and including wanting the homeland to be attacked.

If anyone has engaged in fear mongering on this issue, it is Paul. We know there is a clear and present danger to the nation from Islamist terror groups like al-Qaeda and ISIS. And we also know that lone wolf terrorists, who are either inspired by foreign groups or in contact with them, are a real threat. While Paul claims that there is no proof that metadata collection has prevented a single attack, that is mere sophistry. It is self-evident that allowing the government to be made aware when someone in this country contacts a known terror suspect or group is an essential tool for maintaining U.S. security. Just as important, he can’t point to a single instance of abuse of this basically inoffensive program. This isn’t government spying. It’s common sense.

But instead, Paul sought to feed paranoia about the government by asserting that collecting the records of conversations — though not the conversations themselves — is somehow a threat to liberty. Though Americans always do well to be suspicious of government power, the notion that the right to conduct conversations with terrorists without these communications being detected by American intelligence is not one that is basic to the defense of liberty. Though his point is that the PATRIOT Act forces us to give up our liberty for security while preserving neither, this is untrue. Preventing the government from being able to access these records is injurious to the liberty of all Americans because doing so gives those who would destroy it the ability to evade detection.

Those who wave the flag of individual rights and liberty on this issue should remember that this is not a tax or a restriction on the ability of Americans to conduct their lives as they see fit. This is, instead, the government seeking to carry out a mission that only it can effectively do: To, as the preamble to the Constitution states, “provide for the common defense.” There is no more essential duty of government, even a limited government animated by concerns about liberty, than to defend us against terrorism. Though Paul says he, too, wants to fight the terrorists, his campaign against the PATRIOT Act and his longstanding opposition to defense spending shows that he wishes to do so on the cheap and while also depriving the government of some of the basic tools it needs in the age of mobile phones and the Internet.

But Paul’s grandstanding in the Senate is about more than his marginalization or the weak scaremongering arguments he has used. His willingness to allow the PATRIOT Act to expire without a replacement merely in order to make a point is the height of irresponsibility, especially from someone who wants to be commander-in-chief. His conduct on the floor of the Senate also shows that he is an intemperate man who is willing to spin fantasies about government conspiracies and then claim those on the other side are secret supporters of atrocities.

Paul’s position seems better suited for discussion on some extremist Internet site or Listserv in the fever swamps of paranoia than the U.S. Senate, let alone a future president. Some of his Senate antagonists are claiming that he has gone this route to drum up funds for his presidential campaign. Maybe so, as he needs his father Ron’s old libertarian base to pony up more cash for him in order to keep him in the race. But this disgraceful exhibition demonstrated conclusively just how quixotic that effort has become.