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' Jayce Henderson, Will Cantine and Jordan Mazza

BOSTON MARATHON ABC News' Benjamin Bell: " Rep. Michael McCaul Expresses Concern Over Potential Marathon Terrorist Copycat" This morning on "This Week," House Homeland Security Committee Chair Rep. Michael McCaul, R-Texas, while noting the increase in security in Boston ahead of the marathon tomorrow, expressed concern over the potential that someone may try to replicate the attack last year on the Boston Marathon that left three people dead and hundreds injured. "I do believe it's very ramped up security wise, cameras, personnel, canines, all sorts of bomb detecting equipment. So I do think it's very well fortified. It'd be difficult to penetrate that," McCaul said on "This Week" this morning. "I am concerned, as was noted, a copycat type demonstration, or someone who was inspired by the Tamerlan brothers, Tamerlan Tsarnaev, to perpetrate another act of jihadism. That's a very real scenario." LINK

RUSSIA // UKRAINE Bloomberg's Kateryna Choursina and David Lerman: " Ukraine Separatists Hold Ground As U.S. Eyes Sanctions" Shootouts in eastern Ukraine over the weekend led to calls for more U.S. economic sanctions against Russia, as a diplomatic accord aimed at defusing the crisis showed little sign of taking hold. Ukrainian and Russian officials traded accusations over responsibility for tensions that escalated since last week's signing of an agreement in Geneva that sought disarmament of all illegal groups and vacating of all seized buildings. LINK

The Washington Times' Rowan Scarborough: " Tactical Advantage: Russian Military Shows Off Impressive New Gear" Elite Russian troops are displaying a new arsenal of body armor, individual weapons, armor-piercing ammunition and collar radios - a menu of essential gear that gives them a big tactical advantage against a lesser-equipped Ukrainian army. If President Vladimir Putin orders an invasion, the new-generation body armor, in particular, would provide exceptional protection against small arms if Russian troops go street by street to capture Kiev and other cities. LINK

The Hill's Peter Sullivan: " Ukraine Threatens To Undermine Obama's Delayed Asia 'Pivot'" President Obama is traveling to Asia this week under the cloud of the Ukraine crisis, which threatens to put Asian allies on edge about U.S. security commitments and create yet another distraction from the administration's much-delayed "pivot" to the region. Obama will be visiting Asian allies, including Japan, South Korea and the Philippines, that are involved in increasingly tense territorial disputes with China, and will seek to reaffirm U.S. commitment to them. That connection was supposed to have been cemented earlier in Obama's tenure, when the administration announced a "rebalance," or "pivot," to Asia. But crises at home and around the world, the latest of which is in Ukraine, have stymied that plan. LINK

The Wall Street Journal's William Mauldin, Carol E. Lee and Jay Solomon: " U.S.-Russia Relations Come Full Circle After Ukraine" When then-Prime Minister Vladimir Putin was seeking to return as Russia's president in December 2011, he watched as Moscow's streets filled with the biggest anti-Kremlin rallies in years. Mr. Putin played the anti-American card. He charged on state television that the U.S. treated its allies like "vassals," a line he would repeat as he reclaimed the presidency from Dmitry Medvedev, with widespread support. The State Department tried to brush aside Mr. Putin's rhetoric, even suggesting the word "vassals" might have been mistranslated. LINK

USA Today's Aamer Madhani: " Biden Heads To Kiev To Meet Ukraine Leaders" Vice President Biden will begin a two-day visit to Ukraine on Monday amid growing anxiety in Washington that Russia President Vladimir Putin will press to grab more of eastern Ukraine. The vice president was set to depart for Kiev late Sunday after a fragile truce reached last week in Geneva was tested earlier in the day with deadly shootout at a checkpoint run by pro-Russian militants near the town of Slovyansk. Biden is set to meet with Ukraine's interim prime minister, Arseniy Yatsenyuk, parliament Speaker and acting President Oleksandr Turchynov and other key legislators, according to the White House. LINK

PRESIDENT OBAMA The Washington Post's Juliet Eilperin: " During Asia Trip, Obama Will Renew Effort To 'Rebalance' U.S. Relationship With The Region" President Obama departs Tues­day for a week-long, four-nation tour of Asia, where he and his top aides will be less focused on any big policy announcements than on reassuring jittery allies that America remains committed to bolstering its security and economic ties to the region. The trip - rescheduled from October, when Obama canceled his plans because of the government shutdown - includes two of the countries on his original itinerary, Malaysia and the Philippines, as well as Japan and South Korea. LINK

JEB BUSH The New York Times' Michael Barbaro: " Jeb Bush's Rush To Make Money May Be Hurdle" As it sought to recruit well-heeled investors, an untested and unprofitable Miami company named InnoVida brought aboard a trusted Florida figure in 2007: Jeb Bush, the former governor and the brother of a sitting president. For potential stockholders, the imprimatur of Mr. Bush, who joined InnoVida as a paid consultant and a member of the board of directors, conferred credibility on the young start-up. LINK

RICK PERRY Politico's Katie Glueck: " Rick Perry's Extreme Makeover" It's impossible to exorcise the memories of 2012. But Rick Perry is going all out to present a new and improved version of himself - the swaggering big-state governor of old, with a dash of seasoned wise man thrown in. In the early months of 2014, his political team has booked him on one high-profile program after another: He's joked with Jimmy Kimmel, charmed the "Morning Joe" crowd and wowed the Conservative Political Action Conference. The Texas Republican's hip glasses are still earning approving media mentions long after he first donned them. And the possible 2016 candidate has spent time with early-state types in Iowa (and in late 2013, South Carolina), while also mixing it up in more exotic locales from Davos to Palau. LINK

ABC NEWS VIDEO " 'This Week': John Paul Stevens" LINK " 'This Week'" Powerhouse Puzzler" LINK " 'This Week': Powerhouse Roundtable" LINK " 'This Week': The Religious Right" LINK " 'This Week': Faith And Politics" LINK " 'This Week': Boston Marathon Security" LINK '" This Week': Yemen Drone Strike" LINK " Political Impact Of Chelsea Clinton's Pregnancy On Hillary's Campaign" LINK " Drone Kills Militants, Civilians In Yemen" LINK " Boston Marathon 2014 Security At An Extraordinary Level" LINK " Ukraine Firefights Threaten To Drag US Further Into Conflict" LINK

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