FACTBOX: Massachusetts and its February 5 primary

(Reuters) - Massachusetts is one of 24 U.S. states that holds its presidential nominating contest on February 5.

Following are a few facts about the Bay State and its primary:

* Republicans, including presidential candidate Mitt Romney, controlled the governor's mansion between 1991 and 2007. Otherwise, the Democratic Party has long dominated state politics. Both U.S. senators and all 10 members of the Massachusetts delegation in the House of Representatives are Democrats, and the governor's mansion and state legislature are currently in Democratic hands.

* This Democratic pedigree is reflected in the relative emphasis each party gives the state. Massachusetts will send 121 delegates to the Democratic convention but only 43 delegates to the Republican convention.

* Polls close at 8 p.m. EST. Both primaries are open to independent voters.

* Democratic candidate Barack Obama is backed by the state's three senior politicians: Gov. Deval Patrick; Sen. John Kerry, the party's 2004 presidential nominee; and Sen. Edward Kennedy. Nevertheless, recent polls show the Illinois senator trailing rival New York Sen. Hillary Clinton by an average of 18 percentage points.

* On the Republican side, recent polls show Romney leading rival Arizona Sen. John McCain by an average of 25 percentage points.

* The state's professional sports teams have been remarkably successful in recent years. Baseball's Boston Red Sox won the World Series in 2004 and 2007, while the New England Patriots football team ended an otherwise-perfect season with a Super Bowl loss on Sunday. The team has won three championships since 2002.

(Reporting by Andy Sullivan; Vicki Allen)

SOURCES: American Almanac of Politics, Real Clear Politics, U.S. Census Bureau

(For more about the U.S. political campaign, visit Reuters "Tales from the Trail: 2008" online at http:/blogs.reuters.com/trail08/)