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, Amanda VanAllen and Carrie Halperin

SENATE ABC News' Shushanna Walshe: " Ed Markey, Gabriel Gomez Win Senate Primaries in Massachusetts" Democratic U.S. Rep. Ed Markey, D-Mass., and Republican businessman Gabriel Gomez are the winners in Tuesday's primary for the special election to fill the U.S. Senate seat vacated when John Kerry became Secretary of State. Markey, a House member since 1976, bested U.S. Rep Stephen Lynch, D-Mass., and Gomez beat out former acting ATF director and former U.S. Attorney Michael Sullivan, as well as state legislator and former general counsel to Mitt Romney, Dan Winslow, the Associated Press determined. LINK

BOSTON BOMBINGS The Hills' Jordy Yager: " Senate panel to probe Boston intel issues" The Senate announced plans Tuesday to hold hearings on the Boston Marathon bombings as Republican criticism mounts over the administration's handling of intelligence leading up to the attack. The upper chamber's move came as President Obama defended intelligence and law enforcement agencies and their willingness to share information in the months prior to the bombings. LINK

The New York Daily News' Stephen Rex Brown: " President Obama vows to review security missteps that failed to stop Boston Marathon bombing" President Obama ordered a full review Tuesday of how the government handled intelligence leading up to the Boston Marathon bombings. The review, which will last 90 days, will also examine whether the government can do more to stop people who become radicalized within the United States. LINK

HEALTHCARE The Los Angeles Times' Noam N. Levey: " Obama seeks to allay healthcare law concerns" President Obama sought to tamp down fears Tuesday that his landmark healthcare law would raise insurance costs and cause other disruptions, saying most Americans were already benefiting from it and others soon would. "Any time you're implementing something big, there's going to be people who are nervous," the president said at a news conference at which he delivered a new pitch for the 2010 legislation. LINK

FOREIGN AFFAIRS The Washington Times' Guy Taylor: " State Department downplays reports of Benghazi bullying" The Obama administration found itself in the cross hairs of mounting Republican frustration Tuesday over national security policy, with particular focus on unanswered questions surrounding the Boston Marathon bombings last month and the terrorist attack last year on the U.S. Consulate in Benghazi, Libya. With 134 Republican members of the GOP-controlled House now signed on to a bill that would create a select committee to investigate the Benghazi attacks,Sen. Lindsey Graham, South Carolina Republican, seethed that U.S. national security has "deteriorated" under President Obama's watch. LINK The New York Times' Mark Landler and Rick Gladstone: " Obama Considers Expanding Support for Syrian Rebels" The White House is once again considering supplying weapons to Syria's armed opposition, senior officials said Tuesday. Such a decision would be a policy shift for the Obama administration, which has stepped up its nonlethal aid but stopped short of lethal weaponry and has expressed reluctance about greater military entanglements in the Syrian civil war. LINK

The Washington Post's Karen DeYoung: " Obama moving toward sending lethal arms to Syrian rebels, officials say" President Obama is preparing to send lethal weaponry to the Syrian opposition and has taken steps to assert more aggressive U.S. leadership among allies and partners seeking the ouster of President Bashar al-Assad, according to senior administration officials. The officials said they are moving toward the shipment of arms but emphasized that they are still pursuing political negotiation. LINK

IMMIGRATION Politico's Carrie Budoff Brown: " Gay Rights push threatens immigration deal" The most serious threat to bipartisan immigration reform doesn't involve border security or guest workers or even the path to citizenship. It's about gay rights. Senate Judiciary Committee Chairman Patrick Leahy (D-Vt.) has told advocates that he will offer an amendment during the bill markup next week allowing gay Americans to sponsor their foreign-born partners for green cards, just as heterosexual couples can. The measure is likely to pass because Democrats face pressure from gay rights advocates to deal with it in committee, rather than on the Senate floor, where the odds of passage are far less favorable. LINK

SHARIA LAW USA Today's Cathy Lynn Grossma: " Report: Muslims back Islamic law, disagree on meaning" Devotion to Islam shapes the lives of most Muslims but their views on democracy, religious law known as sharia, and family life are varied, a new study finds. The research report on Muslim views on religion, politics and society was released Tuesday by The Pew Research Center's Forum on Religion & Public Life. LINK

HIGH-SPEED TRADING The Wall Street Journal's Scott Patterson, Jenny Strasburg, and Liam Pleven: " High-Speed Traders Exploit Loophole" High-speed traders are using a hidden facet of the Chicago Mercantile Exchange's computer system to trade on the direction of the futures market before other investors get the same information. Using powerful computers, high-speed traders are trying to profit from their ability to detect when their own orders for certain commodities are executed a fraction of a second before the rest of the market sees that data, traders say. LINK

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