Simplify the following text for a Grade 12 native English-speaking person.
Original: Maurice Robert `` Mike '' Gravel ( ; born May 13 , 1930 ) is a former Democratic United States Senator from Alaska , who served two terms from 1969 to 1981 , and a former candidate in the 2008 presidential election .
Simplified: Maurice Robert Gravel , better known as Mike Gravel ( born May 13 , 1930 in Springfield , Massachusetts ) is an American politician , a member of the Democratic Party .