Former Texas Gov. Rick Perry at a town hall meeting in Milford, N.H., on April 16. (Associated Press/Charles Krupa)

Sen. Marco Rubio (R-Fla.) for some time has made the argument that a senator such as himself is better prepared to be commander in chief. On Saturday in Iowa he upped the ante, telling an Iowa radio host, “I believe that I take over on Day One as president prepared to lead this country in the most crucial obligation the president faces, as commander in chief,” Rubio said. “Governors can certainly read about foreign policy, and take briefings and meet with experts, but there is no way they’ll be ready on Day One to manage U.S. foreign policy.”

Wisconsin Gov. Scott Walker retorted later in the day, “In my lifetime, the best president when it comes to foreign policy was a governor from California. In my lifetime, the worst president for foreign policy was a freshman senator from Illinois.”  He fired back at Rubio: “He’s questioning how Ronald Reagan was ready,” he told reporters. “I believe that Barack Obama shows that as a first-term senator, he isn’t prepared to lead — at least not in the case of Barack Obama. Governors innately have the ability to lead. Every day we’re required to use our status to make decisions — not just give speeches, not just to travel to foreign places — but to ultimately make decisions.”

Coincidentally that morning former Texas governor Rick Perry was giving a very well-received speech in Las Vegas to the Republican Jewish Coalition on foreign policy. He was impressive (more about that in a minute) and got enthusiastic ovations. Rubio of course is also facing Jeb Bush, who has an encyclopedic understanding of international issues, and potentially Ohio Gov. John Kasich, who served on both the House Budget and Armed Services committees and displays command of the issues.

Rubio is certainly impressive in his own right, and he is arguably the most eloquent in the field. But should he really be planting his flag on the “I’m a senator” hill? Certainly it overstates the case to say no governor can be ready. Moreover in doing so he calls attention to his status as a freshman senator. A better tactic would be to show voters his expertise, as he did at the Koch summit this year, rather than arguing that senators have the edge because they are senators. In the debates Rubio can test the limits of Walker’s foreign policy knowledge, but for now he might do well to press his opponents to be as specific as he has been on a range of foreign and domestic matters. (When asked what agenda he would bring to Washington D.C., Walker often falls back on a formulaic statement that he wants to “take power out of the hands of the special interests and give it back to the hardworking taxpayer.”)

All of this scuffling may wind up playing into the hands of a candidate like Perry, who is the only one with military experience and who has been strong on defense and staunchly pro-Israel since both Walker and Rubio were in college. When I spoke to Perry by phone after his RJC speech, he said the most common question he is asked is how he would he restore America’s image in the world and its relationship with Israel. He cracked, “I tell them that’s probably one of the easier jobs. Moshe Alon [Israel’s defense minister] would probably dance a jig if he learned Rick Perry is going to the White House.” He continued, “My relationship are not just professional relationships. These are personal relationships.” He recalled visits with current Prime Minister Benjamin Netanyahu. He then shifted to a broader topic. “How do we recover?” he asks about the post-Obama foreign policy. “I go back to 1979 and Jimmy Carter.” He ticks off the similarities to the current situation — a hollowed out military, the Soviet invasion of Afghanistan, the Iran hostage situation and the failed rescue attempt. “There was great distrust [of the United States]. We were in a funk.” And then came Ronald Reagan and America was back, he says. “We are a resilient country. We survived the Civil War. We survived two World Wars. We survived Jimmy Carter and we will survive this president.” He reiterates, “I know as sure as the sun rises in the East that the best days of America are still ahead.” So yes, a governor can inspire and lead.

As for the specifics, Perry’s speech took the audience around the globe as he emphasized his differences with President Obama. He argued — correctly to my mind — that Obama has departed from a bipartisan consensus that America must lead. “But that consensus does not hold with the Obama administration as demonstrated by its negotiations with Iran.” He continued:

Ignoring the lessons of history, our president aims to sign an agreement with a nation that is the world’s largest state sponsor of terrorism — the Islamic Republic of Iran — which we are told on paper limits Iran’s nuclear ambitions but in reality it legitimizes them. It is a dangerous deal, and for the sake of peace in the Middle East it must be stopped. We must understand that Iran’s ambitions extend beyond their stated vow to destroy Israel. They aim to become the undisputed power of the Middle East. Today they already dominate four Arab countries: Iraq, Lebanon, Syria and Yemen have all become, or are becoming, Iranian client states. Iran has increasing control of the fight in Iraq, as they assist the government’s efforts to stop ISIS.

For decades, [Iran’s] money and arms have flowed to Hezbollah and Hamas fighters. And the Houthi militia has taken control of Yemen’s capital, where chaos reigns, and Saudi Arabia has responded with a bombing campaign. American ships are now positioned to block the shipment of weapons from Iran to the Houthi rebels. If we can’t even trust Iran when it comes to arming rebels in Yemen, how can we trust them to live up to a nuclear agreement? Should they develop nuclear weapons, then it is only a matter of time before we see procurement of a Sunni bomb a weapons escalation that endangers the entire Middle East. The Iranian negotiations have already produced grave consequences with Russia — announcing it would end financial sanctions and sell the Iranians surface-to-air missile systems. But long before this development, the Russian president had acted aggressively in response to our weakness toward Iran, ISIS and Syria. Putin was watching when our president drew a red line in Syria that was crossed without consequence. He saw what happens when a president orders the complete withdrawal of American troops from Iraq with no plan to secure the peace.

Perry sure sounds like he is fully cognizant of the world’s challenges. He continued around the globe, covering Russia, the Baltic states and the rise of radical Islamists and anti-Semitism in Europe. He then dwelt on a topic few candidates and certainly not the president have addressed:

We see in America today, on 115 university campuses, groups like “Students for Justice in Palestine” masquerading as proponents of social justice when they exist to foment hostility toward Israel and to shut down free debate. They are a propaganda tool used to demonize, delegitimize and eliminate Israel. They are not just anti-Israeli, they are anti-American. And yet like all good propaganda tools, they have found a welcome home at liberal universities in America. Our responsibility is this: To expose them for what they are and to be unwavering in our commitment that Israel has the right to exist as a Jewish State.

In short, Rubio will not convince voters he is superior to other candidates on foreign policy because he is a senator. He is extremely knowledgeable and inspiring, but he will have considerable competition from Perry, Bush and, if he continues to learn and travel, Scott Walker. It will be an impressive field and the country can look forward to a robust debate on national security.