[Wolf Blitzer, Cnn Anchor:] Happening now, a Memorial Day explanation from John McCain. The former POW delves into a dispute with Barack Obama over veterans' benefits. And he defends his commitment to America's troops. Also this hour, Hillary Clinton's big push in Puerto Rico. What does she hope to accomplish with just days left in the Democratic primary season? We're going to have that. And we're also going to tell you why Bill Clinton says his wife is the victim of a cover-up. Plus, the Ohio challenge. Can Democrats come together to win a crucial swing state? We're getting the big picture aboard the CNN Election Express. I'm Wolf Blitzer. You're in THE SITUATION ROOM. Up first this hour, Memorial Day in presidential politics. The holiday honoring America's war dead seems to play to John McCain's strong suit as a former POW and the only major candidate who served in uniform. But today McCain felt compelled to strongly defend his vote against repeat, against the veterans benefit bill, a vote that has been sharply criticized by Barack Obama, among a lot of others. We begin our coverage with CNN's Mary Snow. She's covering McCain's holiday appearance out in New Mexico, watching this story for us. All right, Mary. Update our viewers. This is a huge battle, and it's getting personal between Barack Obama and John McCain over veterans' benefits. What's going on?
[Mary Snow, Cnn Correspondent:] Well, Wolf, this has been a battle that's been brewing over the past couple of days. Now, today, Senator McCain and Senator Obama refrained from specifically targeting each other on this Memorial Day, but here in Albuquerque earlier today, Senator McCain did defend his stance on that GI bill that's become a point of contention on the campaign trail.
[Snow:] Senator John McCain marked Memorial Day with fellow veterans in Albuquerque. He talked about patriotism but didn't avoid politics. He responded to criticism from Democrats, particularly Senator Barack Obama, for opposing a GI bill that would extend education benefits to veterans. He didn't mention Obama by name, but he did refer to fellow veteran Senator Jim Webb, who introduced the bill.
[Sen. John Mccain , Presidential Candidate:] It would be easier, much easier politically, for me to have joined Senator Webb in offering his legislation.
[Snow:] The bill applies to people who have three years of service. McCain says he's concerned it would encourage people to leave the military after one enlistment. He wants the benefits tied to length of service.
[Mccain:] At a time when the United States military is fighting in two wars and we're finally, finally beginning the long, overdue and very urgent necessity of increasing the size of the Army and Marine Corps, one study estimates that Senator Webb's bill will reduce retention rates by 16 percent.
[Snow:] But others, including Obama, say it would encourage enlistment. And Obama has been targeting McCain for his opposition.
[Sen. Barack Obama , Presidential Candidate:] I don't understand why John McCain would side with George Bush and oppose our plan to make college more affordable for our veterans. Putting a college degree within reach for our veterans isn't being too generous. It's the least we can do for our heroes.
[Snow:] And the argument has turned personal, with McCain highlighting his military service.
[Mccain:] I take a backseat to no one in my affection, respect and devotion to veterans. I grew up in the Navy.
[Snow:] McCain last week took aim at Obama, saying he didn't need to be lectured by someone who chose not to serve in the military. A charge Obama says made no sense.
[Obama:] I didn't serve, as many people my age, because Vietnam was over by the time I was of draft age.
[Snow:] And Wolf, Senator Obama is also here in New Mexico. Just a short time ago he paid tribute to veterans in Las Cruces, New Mexico. He did not mention Senator John McCain by name, but he did talk about his own personal history, mentioning and talking about the fact that his grandfather served in World War II Wolf.
[Blitzer:] All right, Mary. Thank you. Barack Obama, as Mary said, is in New Mexico. That's a key battleground state in his likely match-up with McCain in the fall. We're going to have a full report on Senator Obama's day. That's coming up shortly. While Obama and McCain campaign out in the Southwest, Hillary Clinton is more than 2,000 miles away in Puerto Rico right now. She's making a major push before Sunday's primary in Puerto Rico with time almost out in this primary season. Let's go out to San Juan. Our Suzanne Malveaux is joining us now live. She's watching this story. Senator Clinton is there, what, with her whole family? Are they that much involved in trying to get the vote out in Puerto Rico, Suzanne?
[Suzanne Malveaux, Cnn White House Correspondent:] Absolutely, Wolf. I mean, this is a very important contest for Hillary Clinton. There are two sayings that are going around right now in Puerto Rico. One is, "Si, puedemos." That is, "Yes, we can." Barack Obama here on Saturday, but it was a quick visit. This is the message from Hillary Clinton in the local paper it is "Any time, any place," challenging Barack Obama to yet another debate over Puerto Rican issues. The whole family here emphasizing that they're going to campaign very hard for the last remaining big contests.
[Sen. Hillary Rodham Clinton , Presidential Candidate:] I will come to Puerto Rico. I promise.
[Unidentified Male:] Thank you. Thank you.
[Clinton:] I will be a president who actually comes to Puerto Rico.
[Malveaux:] For Hillary Clinton, campaigning in Puerto Rico is a family affair.
[Unidentified Male:] How many grandchildren all together now? Wow. She said that she she lost count.
[Malveaux:] Several events were set up in people's homes to convey a sense of being intimately involved.
[Clinton:] If he makes a career in the Army, that when I'm president we'll begin ending the war in Iraq. And you will not have to worry about him going back to Iraq. That's what I hope.
[Malveaux:] Clinton also brought her own family...
[William Jefferson Clinton, Fmr. President Of The United States:] But in Puerto Rico...
[Malveaux:] ... to remind voters how good her husband's administration had been to the island, providing federal aid following Hurricane George and getting rid of the controversial bombing range in Vieques. If Barack Obama wins Puerto Rico in six days, he will reach the critical threshold in delegates to become the Democratic nominee. But Clinton is the favorite here, expected to pick up more delegates and votes. So maintaining her lead here means another day in the race. And Wolf, some of the key issues when it comes to Puerto Ricans her is obviously the status of Puerto Rico, now a commonwealth. Some pushing for statehood or independence. Hillary Clinton saying that she would leave it up to the Puerto Ricans to decide what is in their best interest, but that she would deal with that within her first term. Also bringing an end to the Iraq war, two issues that she talked about earlier today. There are four million Puerto Ricans here. There's another four million on the mainland. And she is certainly hoping hoping, Wolf, that that is going to work in her favor Wolf.
[Blitzer:] Suzanne Malveaux looking ahead to Puerto Rico on Sunday. Thanks, Suzanne, very much. Fifty-five delegates up for grabs in Puerto Rico's primary. It has more delegates at stake than over half of the states that held contests this primary season. As an unincorporated territory, Puerto Rico has a say in the primary process, but not repeat, not in the general election in November. Residents of the Spanish-speaking Caribbean island do not get to vote in November. A familiar Memorial Day scene President Bush laying a wreath at the Tomb of the Unknowns at Arlington Cemetery. The last time he'll mark this holiday as commander in chief. It was an emotional day for Mr. Bush as he got closer to turning over the reins to a new president. Let's hear from him and from the candidates who likely will face off for his job in the fall.
[George W. Bush, President Of The United States:] On this Memorial Day, I stand before you as the commander in chief and try to tell you how proud I am of the sacrifice and service of the men and women who wear our uniform. They're an awesome bunch of people, and the United States is blessed to have such citizens.
[Obama:] On this day of all days, let's memorialize our fallen heroes by honoring all who wear our country's uniform and by completing their work to make sure America is more secure and our world is more free. But let's also do our part, service member and civilian alike, to live up to the idea that so many of our fellow Americans have consecrated. The idea of America, that is the essence of patriotism. That is the lesson of this solemn day. And that is the task that lies ahead. God bless you and may God bless the United States of America.
[Mccain:] Your ambitions may not have led you to war. The honors you sought were not kept hidden on battlefields. Many of you many of you were citizen soldiers. You answered the call when it came, took up arms for your country's sake, and fought to the limit of your ability, because you believed America's security was as much your responsibility as it was to the professional soldiers. And when you came home, you built a better country than the one you inherited. It is a privilege and an honor to be in your company.
[Blitzer:] We're waiting to hear from Hillary Clinton. She's about to make some statements, presumably on this Memorial Day holiday about the men and women in uniform. Once she does, we'll bring you her comments as well. Jack and "The Cafferty File" have the day off. They'll be back tomorrow. Barack Obama is in the early stages of his vice presidential search. Could he use a Florida connection?
[Bob Graham , Fmr. U.s. Senator:] The reality is, if the nominee of your party for president of the United States asks you to serve in almost any capacity, most people are going to say yes.
[Blitzer:] The former senator Bob Graham tells us if he's gotten any feelers from the Obama campaign about the number two job. Plus, the true meaning of Memorial Day. U.S. troops carrying on in Iraq after losing five repeat, five of their comrades. CNN's Arwa Damon revisits the men of Delta Company. And you'll need to look closely if you want to catch a glimpse of President Bush raising campaign cash for John McCain. We'll tell you why right here in THE SITUATION ROOM.