The Note's Must-Reads are a round-up of today's political headlines and stories from ABC News and the top U.S. newspapers. Posted Monday through Friday right here at www.abcnews.com

Compiled by ABC News' Jacqueline Fernandez, Amanda VanAllen, Carrie Halperin and Alicia Tejada

SANTORUM/ROMNEY ABC News' Gary Langer: " Santorum's Favorability Advances, Matches Romney Among Republicans" Rick Santorum's popularity has jumped since his Feb. 7 trifecta, matching Mitt Romney's among Republicans, surpassing Romney among very conservative Americans and putting Santorum ahead in strength of sentiment, potentially an important factor in the GOP contest. Romney also has gained some ground among strong conservatives, and both candidates are popular with six in 10 Republicans. But the latest ABC News/Washington Post poll finds both well below the levels of favorability enjoyed by front-runners in either party four years ago. LINK

Bloomberg's John McCormick: " Romney Under Pressure to Check Santorum Momentum in Must-Win Michigan Race" For Mitt Romney and Rick Santorum, Michigan may be their political Gettysburg. If Romney loses in his native state, where his father was governor, it would be a defeat from which he might not recover.  The makeup of the Republican electorate, which is likely to be one-third Catholic and opposed to abortion, will help Santorum offset the allegiance Romney draws from supporters who delivered his 2008 presidential primary win over John McCain. LINK

The Boston Globe's Michael Levenson: " Santorum surge forces Romney to shift focus" Rick Santorum's surge in national polls is prompting Mitt Romney to begin talking more explicitly about his own conservative social views, in an attempt to blunt Santorum's appeal to the Republican base. Romney had hoped to stay focused squarely on his economic message and downplay social issues that his advisers believe did not play to his strengths as a onetime businessman, Massachusetts governor, and Winter Olympics chief. LINK

RICK SANTORUM ABC News' Shushannah Walshe: " Rick Santorum in Discussions to Receive Secret Service Protection" Rick Santorum said Tuesday evening "for the sake" of his family he is in talks to possibly acquire Secret Service protection. "We are talking about that right now," Santorum told reporters before referring to events that transpired Monday evening. LINK

ABC News' Elicia Dover: " Santorum 'Completely Misunderstands' Modern Warfare, Gingrich Says" Republican presidential candidate Newt Gingrich said today that Rick Santorum has a "complete misunderstanding" of modern warfare. Gingrich was responding to comments Santorum made Thursday on CNN when the former was asked about the Pentagon's plan to allow more women to fill combat roles in the military. LINK

USA Today's Jackie Kucinich: " Santorum still hasn't released tax returns" Former Pennsylvania senator Rick Santorum told CNN last week he would release his tax returns "in the next couple days," but five days later he hasn't released them. Santorum said on Feb. 9 he would release them "pretty soon" and then narrowed that to "a couple of days." LINK

The Washington Post's Dan Balz " Can Rick Santorum become more than 'not Romney'?"  This is Rick Santorum's week - in the polls, that is. It was his week last week, too, at least on Tuesday night, when he won Republican presidential primary contests in Minnesota, Missouri and Colorado. He got no guaranteed delegates, but those victories surely turned him into the latest matinee idol of conservatives and gave him a tremendous boost in the polls.  LINK

MITT ROMNEY The Wall Street Journal's Joseph B. White and Neil King Jr.: " Romney Races to Defend Michigan" Amid signs Rick Santorum could win an upset victory in Michigan, Mitt Romney escalated his campaign to win the state's Republican primary by taking on the powerful auto union and reigniting the debate over the federal bailouts of two Detroit auto makers. Mr. Romney, writing in a Detroit News editorial-page column Tuesday, attacked as "crony capitalism on a grand scale" the Obama administration's $81 billion auto-industry bailout nearly three years ago. LINK

The Los Angeles Times' Michael A. Memoli:  " Tale of dog's harrowing ride returns to bite Romney" They say if you want a friend in politics, get a dog. In the latest sign of Mitt Romney's struggles, even canines are turning against him. Well, that's not entirely true - we haven't seen any good polling on who dogs prefer among the GOP candidates for president. But some of their human friends are making their feelings known. A group of pet lovers protested outside the Westminster Dog Show in New York on Tuesday afternoon, using the event to revive a well-known saga involving one of Romney's former pets.  LINK

NEWT GINGRICH Politico's Ginger Gibson: " Callista Gingrich steps up role in Newt's 2012 campaign" Callista Gingrich is coming out of her husband's shadow. She delivered an introduction to Newt Gingrich at the Conservative Political Action Conference in Washington, D.C., on Friday. And on Tuesday, Gingrich delivered her first solo performance as a campaign surrogate for her husband by speaking to a group of Republican women at a burger chain here.  LINK

DEMOCRATS The Hill's Josh Lederman:  "LA Mayor Villaraigosa to chair Democratic convention" Los Angeles Mayor Antonio Villaraigosa (D) will chair the Democratic National Convention in Charlotte, N.C. in September, a Democratic source confirmed. The post will give Villaraigosa, a rising star in the Democratic party, a prominent platform to raise his profile on the national stage. It also gives him a central role in efforts to reelect President Obama, retake control of the House and maintain a Democratic majority in the Senate.  LINK

BUDGET New York Times' Jennifer Steinhauer " Tentative Deal Reached to Preserve Cut in Payroll Tax"  Members of a House-Senate committee charged with writing a measure to extend a payroll tax reduction and provide added unemployment benefits reached a tentative agreement Tuesday evening, with Republicans and Democrats claiming a degree of political victory in a fight with significant election-year implications.  LINK

ABC NEWS VIDEOS " Flashback: Santorum Caught in Malpractice Doubletalk" LINK " Santorum Heckled By Occupy Protesters" LINK

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