	Introduction

Leaders in both chambers of Congress have indicated that immigration reform is a legislative priority in the 113 th Congress. The main elements of "comprehensive immigration reform" (CIR) legislation typically include increased border security and immigration enforcement, improved employment eligibility verification, revision of legal immigration, and options to address the millions of unauthorized aliens residing in the country. Several of these elements also were among the features that President Barack Obama emphasized later the same month when he called for the 113 th Congress to "quickly" take up CIR legislation, though President Obama has not endorsed new temporary worker visas. Similar to President Obama's recent statements on CIR, former President George W. Bush stated that comprehensive immigration reform was to be a top priority of his second term. President Bush's principles of immigration reform included increased border security and enforcement of immigration laws within the interior of the United States, as well as a major overhaul of temporary worker visas, expansion of permanent legal immigration, and revisions to the process of determining whether foreign workers were needed. Then—as well as now—the thorniest of these issues centered on unauthorized alien residents of the United States. Substantial efforts to enact CIR legislation failed in the 109 th and 110 th Congresses, prompting some to characterize the issue as a "third rail" that is too highly charged to touch. The three major bills CIR bills that received floor action were
Border Protection, Antiterrorism, and Illegal Immigration Control Act of 2005 ( H.R. 4437 as passed by the House in the 109 th Congress), Comprehensive Immigration Reform Act of 2006 ( S. 2611 as passed by the Senate in the 109 th Congress), and Comprehensive Immigration Reform and for other purposes ( S. 1639 as considered by the Senate in 110 th Congress)
This report opens with brief legislative histories of CIR in the 109 th and 110 th Congresses. CIR in the 109th Congress

During the 109 th Congress, both chambers passed major overhauls of immigration law but did not reach agreement on a comprehensive reform package. These proposed revisions to legal immigration included expanded guest worker visas and increased legal permanent admissions. The major bills would not have made sweeping changes to the inadmissibility grounds, but they would have revised specific grounds pertaining to national security and illegal entry. The three bills would also have added gang membership as a ground for inadmissibility. All three bills would have broadened the categories of aliens subject to expedited removal. All three bills would have increased the criminal penalties for immigration and document fraud. All three bills would have expanded the categories of aliens subject to mandatory detention. The House-passed bill in the 109 th Congress would have criminalized unauthorized presence. In contrast, the Senate bills in the 109 th and 110 th Congresses would have created avenues for unauthorized aliens who met a set of criteria and paid prescribed penalties to acquire "earned legalization." 4437 did not contain provisions that would have reformed legal immigration, nor did it have provisions that would have legalized the status of unauthorized aliens in the United States. Comprehensive Immigration Reform and for Other Purposes ( S.  1639 in 110 th Congress)
S. 1639 included provisions aimed at strengthening employment eligibility verification and interior immigration enforcement, as well as increasing border security.
Leaders in both chambers of Congress have listed immigration reform as a legislative priority in the 113th Congress. Most policymakers agree that the main issues in "comprehensive immigration reform" (CIR) include increased border security and immigration enforcement, improved employment eligibility verification, revision of legal immigration, and options to address the millions of unauthorized aliens residing in the country. These elements were among the features that President Barack Obama emphasized when he called for the 113th Congress to take up CIR legislation.
Similar to President Obama's recent statements on CIR, former President George W. Bush stated that comprehensive immigration reform was a top priority of his second term. President Bush's principles of immigration reform included increased border security and enforcement of immigration laws within the interior of the United States, as well as a major overhaul of temporary worker visas, expansion of permanent legal immigration, and revisions to the process of determining whether foreign workers were needed. Then—as well as now—the thorniest of these issues centered on unauthorized alien residents of the United States.
During the 109th Congress, both chambers passed major overhauls of immigration law but did not reach agreement on a comprehensive reform package. In the 110th Congress, Senate action on comprehensive immigration reform legislation stalled at the end of June 2007 after several weeks of intensive floor debate. The House did not act on comprehensive legislation in the 110th Congress.
The three major CIR bills in the 109th and 110th Congresses were the Border Protection, Antiterrorism, and Illegal Immigration Control Act of 2005 (H.R. 4437 as passed by the House in 109th Congress), the Comprehensive Immigration Reform Act of 2006 (S. 2611 as passed by the Senate in 109th Congress), and the Comprehensive Immigration Reform (S. 1639 as considered by the Senate in 110th Congress). All three of the major CIR bills had provisions that would have
increased resources for border security, expanded employment eligibility verification, increased the worksite enforcement penalties, broadened inadmissibility grounds pertaining to national security and illegal entry and added a ground for gang membership, expedited the implementation of the automated entry-exit system known as US-VISIT (United States Visitor and Immigrant Status Indicator Technology), broadened the categories of aliens subject to expedited removal, increased the criminal penalties for immigration and document fraud, and expanded the categories of aliens subject to mandatory detention.
Despite these similarities, there were substantial differences between the chambers regarding the treatment of unauthorized aliens as well as allocations of visas across family and employment categories for future flows of legal immigrants. The House-passed bill in the 109th Congress would have criminalized unauthorized presence. In contrast, the Senate bills in the 109th and 110th Congresses would have created avenues for unauthorized aliens who met a set of criteria and paid prescribed penalties to acquire "earned legalization." The Senate bills also had provisions that would have made substantial revisions to legal permanent admissions, notably revising and expanding the employment-based permanent and temporary visa categories.
The failure of these substantial efforts to enact CIR in the 109th and 110th Congresses has prompted some to characterize CIR as a "third rail" issue that is too highly charged to touch.