(CNN) - Hillary Clinton Thursday jabbed at Sen. Barack Obama for being a first term senator and called her rival for the Democratic presidential nomination a "blank screen."

In an interview on ABC's Nightline Thursday night, Clinton dismissed notion's Barack Obama voters are uninformed, but said the Democratic presidential front-runner aptly described himself in his 2006 book, "The Audacity of Hope."

"I think the best description, actually, is in Barack's own book, the last book he wrote, 'Audacity of Hope,' where he said that he's a blank screen," she said in the interview. "And people of widely differing views project what they want to believe onto him. And then he went on to say, 'I am bound to disappoint some, if not all of them.'"

"He was in the state Senate, what, three years ago, four years ago?" Clinton said in continued jabs. "It's hard to know exactly what his positions are because they have changed rather rapidly in that four-year period. But there is something very appealing, and people have a right to vote for whomever they want."

The comments came a day before the Clinton campaign launched a tough new ad in Texas that aims to portray Clinton as considerably more prepared to handle a foreign policy crises than Obama. Over scenes of sleeping children, the ads narrator asks, "Who do you want answering the phone the phone?" at 3 in the morning.

Obama Campaign Manager David Plouffe forcefully responded to that ad in a conference call with reporters Friday morning."We don't think the ads are going to be effective at all, because Senator Clinton has already had her red phone moment. It was a decision whether to allow George Bush to invade Iraq, and she answered affirmatively," Plouffe said.

- CNN Ticker Producer Alexander Mooney

[cnn-photo-caption image= http://i.cdn.turner.com/cnn/2008/images/02/29/art.obamaex.ap.jpg caption=" The Clinton campaign says Obama needs to win big on March 4, or else he has a problem. "](CNN) - Seeking to raise the expectations for its rival, Sen. Hillary Clinton's campaign said Friday that Sen. Barack Obama needs to sweep the March 4 primaries.

The Illinois senator should win all four states - Ohio, Texas, Rhode Island and Vermont - decisively, given the amount of money and resources he has devoted to them, the Clinton campaign said in a memo circulated to reporters.

"If he fails to garner big wins, there's a problem," the memo states.

"The Obama campaign and its allies are outspending us two to one in paid media and have sent more staff into the March 4 states. In fact, when all is totaled, Senator Obama and his allies have outspent Senator Clinton by a margin of $18.4 million to $9.2 million on advertising in the four states that are voting next Tuesday."

"Senator Obama has campaigned hard in these states," the memo continues. "He has spent time meeting editorial boards, courting endorsers, holding rallies, and – of course – making speeches."

The memo came out moments after Obama campaign manager David Plouffe finished a conference call with reporters, during which he said the New York senator needs big victories in Texas and Ohio Tuesday if she hopes to chip away at Obama's now 153 pledged delegate lead - according to CNN's latest estimate.

"The Clinton campaign needs to begin wining big states by big margins to have any hope of eliminating this delegate lead they are facing," he said.

- CNN Ticker Producer Alexander Mooney

[cnn-photo-caption image= http://i.cdn.turner.com/cnn/2008/images/02/29/art.clintonad.cnn.jpg caption=" Clinton launched a tough new ad Friday."](CNN) - The Democratic White House hopefuls took to the airwaves Friday to battle over national security credentials, with Hillary Clinton’s campaign releasing a tough new ad that pegged her as the presidential candidate best-prepared to take on foreign crises, and Barack Obama’s team responding with the re-release of a spot that painted him as the White House hopeful with the best judgment to be commander-in-chief.

“It’s 3 a.m. and your children are safe and asleep. But there’s a phone in the White House, and it’s ringing. Something’s happened in the world,” says the announcer in the 30-second Clinton spot, which is set begin running in Texas Friday. A phone rings insistently over images of sleeping children.

“Your vote will decide who answers the call. Whether it’s someone who already knows the world’s leaders, knows the military. Someone tested and ready to lead in a dangerous world.

“It’s 3 a.m. and your children are safe and asleep. Who do you want answering the phone?”

The Clinton campaign said the new ad - titled “Children” - is meant to make voters ponder “who they want in the White House during a crisis.”

Within roughly an hour of the ad’s debut, the Obama campaign announced that it was re-releasing “Gulf,” a 30-second spot that first ran prior to the Iowa caucuses. The ad features retired Air Force Gen. Merrill McPeak, a former combat pilot who was the service’s highest-ranking uniformed officer during the first Gulf War.

“As a combat pilot and Air Force chief during Desert Storm, lives depended on the judgments I made,” McPeak says in the spot. “And judgment is what we need from our next commander in chief. Barack Obama opposed this war in Iraq from the start, showing insight and courage others did not.”

McPeak backed John Kerry in the 2004 presidential race.

- CNN Associate Political Editor Rebecca Sinderbrand