The former St. Louis Cardinals slugger, who was among those who testified at the hearing last Thursday, repeatedly declined to answer questions about whether he used steroids. He is sixth on the career home run list with 583.
In December 1998, 87 percent had a favorable opinion of McGwire. During the weekend, that percentage dropped to 53 percent. His unfavorable rating rose from 3 percent to 25 percent.
The poll of 443 baseball fans also showed nine in 10 baseball fans think steroids are at least a serious problem among baseball players, USA Today reported.
The poll was conducted by telephone after Thursday's House Government Reform Committee hearing. In that hearing, Major League Baseball officials and current and former players McGwire, Jose Canseco, Sammy Sosa, Rafael Palmeiro, Curt Schilling and Frank Thomas testified.
Jordana Brewster on Paul Walker: 'He was an enormous presence in my life'
Kate Middleton recycles dress at movie premiere