Hillary Clinton, seemingly days away from being forced out of the presidential field, spent the final weekend before Ohio and Texas voters head to the polls hammering key differences between herself and her chief rival on what, until now, has been Republican turf. Perhaps, the Clinton camp must realize, distinctions on national security are the only way she can beat Barack Obama.

But Clinton's focus on national security, while possibly effective, toe a fine line. The Obama campaign has characterized her language as promoting the "politics of fear," comparing her lines to those Karl Rove might have advised Republicans to use during elections since September 11. Still, with time running out, Clinton has little choice but to try to drive the distinction home.

"My opponent and I are in an important debate about national security and which one of us is best prepared to take charge as Commander in chief," she said Saturday in Fort Worth, according to excerpts provided by her campaign. "He calls that fear-mongering. Well, I don't think Texans scare that easy."

Playing up her national security credentials, Clinton spent much of the weekend surrounded by retired military brass. She touted an endorsement from former Joint Chiefs chairman Hugh Shelton, and her campaign held a conference call with eighteen retired generals and admirals, along with Lee Feinstein, the campaign's national security director. Later, the campaign issued statements on recent rocket attacks on Israel and a tanker deal that Boeing, the American aircraft company, lost to a European rival.

Hoping to convince voters, as she has asserted for months, that she is the candidate of experience, Clinton's campaign even went as far as to draw a subtle link between new Russian President Dmitriy Medvedev and Obama. "Mr. Medvedev has said some hopeful sounding things in the course of his campaign, and the job of a new American President will be to test these words, to see whether they could mark a new approach in Russian politics and foreign policy," she said in a statement.

Obama, though, has not taken the assault lying down. "I have to say, when it came to making the most important foreign policy decision of our generation -- the decision to invade Iraq -- Sen. Clinton got it wrong. She didn't read the nation intelligence estimates," Obama told a crowd in Westerville, Ohio, as The Swamp's John McCormick reported. "I have enough experience to know that if you have a national intelligence estimate ... then you should probably read it."

Susan Rice, Obama's top foreign policy adviser, and several other national security experts backing the Illinoisian's campaign hit back on their own conference call, on which Rice questioned whether Clinton has any more experience on the issues than Obama does.

No matter who wins the primary, both candidates will need to address national security policy against John McCain come the general election. Clinton and Obama, each of whom will likely be put on the defensive by the Arizona senator, are first finding their way against each other. If Obama wins on Tuesday in spite -- or perhaps because of -- Clinton's focus on national security, his chances in November would be greatly improved. And as Clinton's chances seem to be fading, taking the risky step of hitting Obama on national security may be her last hope.