Senator Clinton’s campaign, in an audacious closing argument delivered on the eve of make-or-break primaries in Ohio and Texas, is contending that her qualifications on national security issues outstrip not only those of her rival for the Democratic nomination, Senator Obama, but also the experience of the likely Republican nominee, Senator McCain, who spent nearly six years as a prisoner of war in Vietnam.

“Everybody admires John McCain’s service as a fighter pilot, his courage as a prisoner of war. There’s no issue there,” a retired general in Mrs. Clinton’s camp, Wesley Clark, said in response to a question from The New York Sun yesterday. “But having served as a fighter pilot — and I know my experience as a company commander in Vietnam — doesn’t prepare you to be commander in chief in terms of dealing with the national strategic issues that are involved. It may give you a feeling for what the troops are going through in the process, but it doesn’t give you the experience firsthand of the national strategic issues.”

Speaking along with 17 other former generals, admirals, and senior defense officials on a conference call arranged by Mrs. Clinton’s campaign, Mr. Clark said her seven years of Senate experience and her travels to 80 countries as first lady give her a leg up on the competition. “I think she’s the most experienced and capable person in the race, not only for representing America abroad, but for dealing with the tough issues of national security,” he said.

“I would just say I agree with Wes on that,” a former admiral, William Owens, said. “I think she’s completely ready, and while I too respect Senator McCain’s service enormously, having come from the same service, I would just say that I think Hillary Clinton is the best person and the best-prepared to be our commander in chief.”

Mr. McCain spent 14 years in the Navy as a fighter pilot, a prisoner of war, and, later, commander of a Navy training squadron in Florida. He has been a senator for 21 years and a member of Armed Services Committee throughout. Mrs. Clinton has put in five years on the same panel.

The Arizona senator’s campaign did not respond to telephone and e-mail messages seeking comment for this article.

Traveling in Texas on Saturday, one Clinton surrogate, Gloria Steinem, argued that Mr. McCain’s time in captivity was of no relevance to the presidential race. “I mean, hello? This is supposed to be a qualification to be president? I don’t think so,” she said, according to the New York Observer.

Ms. Steinem, on a speaking tour arranged by the Clinton campaign, said Mrs. Clinton’s lack of service in uniform was actually an asset. “I am so grateful that she hasn’t been trained to kill anybody. And she probably didn’t even play war games as a kid. It’s a great relief from Bush in his jumpsuit and from Kerry saluting,” the Ms. Magazine founder said, according to the Observer.

Mrs. Clinton’s communications director, Howard Wolfson, repudiated Ms. Steinem’s remarks. “Senator Clinton has repeatedly praised Senator McCain’s courage and service to our country. These comments certainly do not represent her thinking in any way,” he said in a statement to the Observer. Mr. Wolfson, who was on the call with the ex-military men, did not opine on their comparisons between Mrs. Clinton and Mr. McCain.

By switching focus to national security in the final stretch before the all-important Ohio and Texas contests, the Clinton campaign risks the appearance of a sort of message schizophrenia. Just weeks ago, her top advisers were asserting that she stood to gain an advantage over Mr. Obama because the slowing economy was turning the race toward pocketbook issues and away from the national security discussion, which inevitably leads to talk about her vote to authorize the war in Iraq.

Now, with hours to go before primaries that none other than President Clinton has declared must-win for his wife, Mrs. Clinton’s brain trust is moving its chips back onto the national security space. The decision may also reflect a careful reading of the polls in Ohio and Texas, the two biggest states voting tomorrow. In Ohio, where the economic angst is greatest, the former first lady looks to be narrowly leading Mr. Obama, 47% to 43%, in a Cleveland Plain Dealer poll. However, in Texas, where the economy is faring better, Mrs. Clinton may be lagging her opponent by a point or two. A Fort Worth Star Telegram/MSNBC poll had the race essentially tied, with Mr. Obama at 46% and Mrs. Clinton at 45%.

Mrs. Clinton’s new ad touting her as the best qualified to take a phone call about a national security crisis at 3 a.m. rolled out in Texas, reflecting her campaign’s conclusion that the Lone Star State may be more fertile ground for such a message.

In their own call with reporters yesterday, supporters of Mr. Obama also took aim at Mr. McCain on the national security front, suggesting he would be too quick to use force. “Senator McCain certainly has a distinguished career but it appears to me that the old adage that when the only tool you know how to use is a hammer, everything looks like a nail,” a former CIA official, John Brennan, said. “I think that is certainly the case with some of his imprudent statements about Iran and others.”

“I think military people would be very, very comfortable” with Mr. Obama, an assistant secretary of defense under President Reagan, Lawrence Korb, said. “This is what they want, a person who understand the limitations of military force and who wants to deal with the real threats.”

A retired vice admiral, Rep. Joseph Sestak Jr. of Pennsylvania, cited Mrs. Clinton’s toughness toward Iran as evidence of her toughness. “As I watched her vote to place the Iranian revolutionary guard, who we’ve known for years has been funneling money to terrorists, through the banks it owns, finally vote to place them on the terrorist list, I came to respect and want badly to support her,” he said.