The United States Census Bureau released the official information on the 2010 Census. After every census, the reapportionment of the nation’s 435 congressional seats occurs based on changes in population. Subsequently, congressional district lines are redrawn by each state.

The biggest winners in the 2010 Census are Texas, which picked up four congressional seats, and Florida, which picked up two congressional seats. Arizona, Georgia, Nevada, South Carolina, Utah and Washington all gained one additional congressional seat. States losing seats include   New York and Ohio with each losing two seats. Illinois, Iowa, Louisiana, Massachusetts, Missouri, New Jersey and Pennsylvania all lose one congressional seat.Thirty-five states have no change in the number of congressional seats.

In February, the U.S. Census Bureau will begin releasing individual state data on population that each state will use in redrawing congressional lines. States redraw congressional districts in a wide array of ways. Some states have nonpartisan commissions that draw lines, others are drawn by the governor and approved by the legislature, and others are drawn solely by the legislature. 

The 2012 election will determine who fills these additional and redrawn congressional districts. Some states that lose congressional seats will be forced to combine congressional districts which could result in one incumbent competing against another incumbent.

These changes will also impact the 2012 presidential election.The number of Electoral College votes each state receives is based partly on the number congressional districts in a given state. For example, if President Barack Obama wins the exact same states he won in the 2008 election, he will receive six fewer Electoral College votes.

Access full data on the 2010 census and a map of congressional districts each state will have in 2012.