Rick Santorum will receive Secret Service protection this week, CNN reports.

So far, Mitt Romney is the only GOP presidential candidate granted protection. USA Today reports Newt Gingrich requested Secret Service protection last week and is awaiting word on whether he will receive the security.

Though a Public Policy Polling survey released late last night showed Mitt Romney regaining the lead over Rick Santorum in the Michigan GOP primary, 39% to 37%, a new Mitchell Research/Rosetta Stone poll shows Santorum taking over the lead back from Romney, 37% to 35%.

A new We Ask America poll shows Romney ahead 37% to 33%.

A new American Research Group survey shows Santorum just ahead, 36% to 35%.

A new Rasmussen survey shows Romney leading, 38% to 36%.

A new Public Policy Polling survey in Arizona shows Mitt Romney is headed for an overwhelming victory in Arizona’s primary on Tuesday. He leads Rick Santorum, 43% to 26%, with Newt Gingrich at 18% and Ron Paul at 11%.

Key finding: “Almost half of those planning to vote have already cast their ballots, and Romney has a 48-25 advantage over Santorum with those folks. That lead makes it nearly impossible for Santorum to make up the difference on election day, and Romney has a 39-27 advantage with those planning to vote on Tuesday anyway.”

A new We Ask America poll shows Romney leading Santorum, 43% to 27%.

A new Quinnipiac poll in Ohio shows Rick Santorum leading the GOP presidential field with 36% of likely Republican primary voters, followed by Mitt Romney at 29%, Newt Gingrich at 17% and Ron Paul at 11%.

Said pollster Peter Brown: “A week out, Sen. Rick Santorum remains seven points ahead among Ohio’s likely Republican primary voters. While almost half the voters say they might change their mind, Santorum supporters seem a little surer of their vote. What happens in Michigan tomorrow night might have an impact on voters in Ohio’s Republican primary.”

A new Politico/George Washington University Battleground Poll “reveals the prolonged nominating battle is taking a toll on the GOP candidates and finds the president’s standing significantly improved from late last year.”

“President Obama’s approval rating is 53%, up 9 percentage points in four months. Matched up against his Republican opponents, he leads Mitt Romney by 10 points (53-43) and Rick Santorum by 11 (53-42). Even against a generic, unnamed Republican untarnished by attacks, Obama is up 5 percentage points. In November, he was tied.”

However, a new USA Today/Gallup poll finds Obama lags his two leading Republican rivals in the 12 swing states likely to determine the outcome of a close race in November.

First Read: “Either Gallup is seeing something that no one else is seeing right now (NBC/WSJ, WaPo/ABC, NYT/CBS), or its methodology is understating Obama’s support and inflating the GOP’s. This isn’t the first time this cycle where Gallup has looked different from the other major national polls.”

“Regardless of the outcome Tuesday in Michigan, Mitt Romney has already lost something big,” Rick Klein observes.

“Romney can solidify his claim on the Republican nomination with a victory in his native state. But what he can’t claim back is the ability to excite and perhaps simply unify the party behind his bid — critical shortcomings that are likely to haunt his bid for the presidency for as long as it lasts.”

Likewise, Jonathan Martin notes Romney’s “pitched battle for his childhood home state also ensures that even a victory here will be viewed as a textbook study of the larger obstacles the former Massachusetts governor faces as the thrill-a-minute Republican primary season continues.”

A new Public Policy Polling survey in Michigan finds Mitt Romney now leading Rick Santorum, 39% to 37%, with Ron Paul at 13% and Newt Gingrich at 9%.

Key finding: “Romney will go into election day with a large lead in the bank. Only 16% of Michigan voters say they’ve already cast their ballots, but Romney has a whooping 62-29 advantage over Santorum with that group. Santorum actually leads Romney 39-34 with those who are planning to cast their votes on Tuesday, but he’d need to win election day voters by even more than that to neutralize the advantage Romney’s built up.”

“Not as closely as some of the most ardent fans, but I have some friends who are NASCAR team owners.”

— Mitt Romney, quoted by CBS News, when asked whether or not he follows NASCAR.

The latest Gallup daily tracking poll shows Mitt Romney overtaking Rick Santorum nationally, 31% to 29%, after he once trailed his rival by double-digits.

“I don’t believe in an America where the separation of church and state
is absolute.”

— Rick Santorum, in an interview on ABC’s This Week.

Nate Silver
notes that while the Republican presidential primary has come down to
collecting delegates on the way to the convention, “the G.O.P.’s
delegate-selection rules are exceptionally complicated and ambiguous.
Many delegates could go to the convention in Tampa either loosely
pledged or entirely unbound to any of the candidates.”

“That means
there will be some wiggle room in the math. Doing things like winning
key states, leading in the aggregate popular vote, leading in national
polls and appearing to have the momentum at the end of the process may
influence the behavior of these unbound delegates. If a candidate can
make a credible claim to having a mandate from the voters, they might
line up behind him. If his claim is poor, they could block his
nomination.”

The Hotline: “The
White House continues to talk about its ability to contest Arizona, but
polling data suggest otherwise — and underscores the fact that
immigration right now is a losing issue for President Obama and
Democrats… While the Hispanic growth in the state is significant, the
percentage of those who are registered is relatively low – and there
have been few signs of any significant uptick in political
participation. The numbers also provide a cautionary tale to the party’s
likely Senate nominee, Richard Carmona, who is an attractive recruit
because of his Hispanic heritage, but could lose support from white
voters over his opposition to SB 1070… There was a good reason
why Janet Napolitano didn’t run for Senate — her involvement in the
White House’s lawsuit against the state immigration law would have
handicapped her campaign from the start.”

Wyoming state representatives “advanced legislation to launch a study into what Wyoming should do in the event of a complete economic or political collapse in the United States,” the Casper Star Tribune reports.

The bill “would create a state-run government continuity task force, which would study and prepare Wyoming for potential catastrophes, from disruptions in food and energy supplies to a complete meltdown of the federal government.”

A new Vanderbilt University poll in Tennessee finds Rick Santorum leading the GOP presidential primary with 33%, followed by Mitt Romney at 17%, Ron Paul at 13% and Newt Gingrich at 10%.

That said, an additional 27% “either said they wouldn’t vote for any of the four major remaining candidates, didn’t know how they would vote or refused to answer.”

The Tennessee primary is on March 6.

“Whether Mitt Romney wins or loses the Michigan and Arizona primaries on Tuesday, his advisers are warning donors and other supporters to prepare for a longer, more bruising and more expensive fight for the Republican presidential nomination that may not be settled until at least May,” the New York Times reports.

“That is prompting a new round of intensified fund-raising by his financial team, which had hoped by this point to be collecting money for a general election match with President Obama. The campaign is increasingly trying to quell anxiety among Republican leaders, while intently focusing on the mechanics of accumulating delegates needed to secure the nomination.”

The Kansas City Star editorial page asked economist Art Laffer — “yes, he of the famous Laffer curve” — whether Rick Santorum would be the Republican presidential nominee.

“Laffer’s answer was non-verbal. His hands went up on each side of his head. He leaned forward, bug-eyed at the imagined horror of Santorum as the GOP nominee — a response that reflects the fears of many on the Republican side.”