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' Carrie Halperin, Jayce Henderson, Amanda VanAllen and J.P. Lawrence

IMMIGRATION REFORM ABC News' Serena Marshall: " Social Media's Immigration March on Washington" The current march on Washington won't fill the National Mall, or see an influx of buses down Constitution Avenue. But what it will do is clog your inbox. You can only see it on your computer, or mobile device, but it's out there: a two- day virtual march on Washington with the goal of demanding immigration reform. LINK

Politico's Carrie Budoff Brown and Manu Raju: " Immigration reform vote search moves to full Senate" Getting immigration reform to the Senate floor took hours of negotiations and committee hearings, hundreds of amendments, a careful orchestration of public statements and backroom pressure to hold the Gang of Eight together. Many of the almost two dozen Republicans identified as possible supporters by the Gang of Eight are demanding changes that would make the bill significantly more conservative. They want stricter border security, tighter control on government benefits for newly-documented immigrants and tougher requirements along the pathway to citizenship. LINK

INTERNAL REVENUE SERVICE USA Today's Gregory Korte: " IRS official refuses to testify in Tea Party probe" The IRS official responsible for tax exemptions refused to testify to a House oversight panel investigating the agency's treatment of conservative groups Wednesday. Citing her Fifth Amendment right against self-incrimination, Lois Lerner would not answer questions about how the IRS developed the "be on the lookout" list for Tea Party groups, what she did when she discovered it, and why she failed to tell Congress about it when asked directly. LINK

The Wall Street Journal's John D. McKinnon and Siobahn Hughes: " Emails Offer New Details on IRS Targeting" Emails and other documents released Wednesday suggest the Internal Revenue Service's procedures used to target conservative groups for added scrutiny were developed by lower-level employees. Republican lawmakers seized on the emails-written in 2011 about decisions made in 2010-as evidence that they were kept in the dark about the practice far too long. LINK

The Washington Post's Philip Rucker and Juliet Eilperin: " On IRS issue, senior White House aides were focused on shielding Obama" As soon as White House counsel Kathryn Ruemmler heard about an upcoming inspector general's report on the Internal Revenue Service, she knew she had a problem. The notice Ruemmler saw on April 24 gave her a thumbnail sketch of a disturbing finding: that the IRS had improperly targeted tea party and other conservative groups. She shared the news with White House Chief of Staff Denis McDonough and other senior White House aides, who all recognized the danger of the findings. LINK

DRONES The New York Times' Charlie Savage and Peter Baker: " Obama, in a Shift, to limit Targets of Drone Strikes" President Obama plans to open a new phase in the nation's long struggle with terrorism on Thursday by restricting the use of unmanned drone strikes that have been at the heart of his national security strategy and shifting control of them away from the C.I.A. to the military. In his first major speech on counterterrorism of his second term, Mr. Obama hopes to refocus the epic conflict that has defined American priorities since the attacks of Sept. 11, 2001, and even foresees an unspecified day when the so-called war on terror might all but end, according to people briefed on White House plans. LINK

ABC NEWS VIDEO " IRS' Lois Lerner: 'I Have Not Broken Any Laws'" LINK

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