Been like that since Reagan, one of the few Presidents in modern times to not have an increase in the minimum wage during his term. Inflation, even though far less than in the 70's, was still pretty high. $100 worth of goods in 1981...cost $136 in 1989...
https://data.bls.gov/cgi-bin/cpicalc.pl?cost1=100&year1=1981&year2=1989
Minimum wage stagnated at $3.35 for the entirety of Reagan's reign. Republicans have talked this game for nearly 40 years...and never come through.
Obama suffers that same minimum wage fate, but his issue has been that obstructionist Congress, as opposed to a lack of proposals.
http://www.dailykos.com/story/2014/3/7/1282880/-Since-1938-Only-Three-Presidents-Have-Never-Signed-a-Minimum-Wage-Increase