Senator Michael Bennet of Colorado, the 21st Democrat to declare his candidacy for president, is known as a moderate who seeks bipartisan compromise. Here’s where he stands on a few key issues.

Immigration

Mr. Bennet may be best known for being part of the so-called Gang of Eight: four Democratic and four Republican senators who negotiated a comprehensive immigration proposal in 2013. The bill, which passed the Senate but not the House, included:

• A path to citizenship for undocumented immigrants who passed a background check, paid a fine and back taxes, and learned English.

• An expanded visa program for agricultural workers and an expedited path to permanent residency for student visa holders who earned advanced STEM degrees.

• A 700-mile border fence, new border-monitoring technologies and about 20,000 more Border Patrol agents.