As usual, the esteemed Nate Silver says it best (link
). Basically, it talks about how Clemens and Bonds should make it even if you ignore the steroids years, while McGwire and Palmeiro would not:
Some voters have sought to apply a standard in which players are given full credit for statistics they compiled during seasons in which they were not suspected of steroid use, while discarding or discounting those in which they were. But Bonds and Clemens would probably have qualified for the Hall of Fame even by this rule. News accounts suggest that Bonds began using steroids after the 1998 season. By that time, he had already won three M.V.P. awards and eight Gold Gloves and had hit 411 home runs and stolen 445 bases. On the basis of Wins Above Replacement, he would have ranked as roughly the 30th best player in baseball history had he retired then. The same sort of reasoning does not work for McGwire, whose signature seasons were associated with steroid use, or for Palmeiro, who was found to have used banned substances late in his career and whose Hall of Fame case rests largely upon his longevity.
In addition, he talks about players who were punished for suspicion of steroids:
The comparison between Bagwell and Biggio may be especially instructive. The suspicion that Bagwell used steroids seems to be based on a sort of stereotyping. Bagwell hit for significantly more power than expected based on his minor-league statistics, and grew heavier and bulkier physically. Slugging first basemen who played in the 1990s are automatically suspected of steroid use by a certain contingent of voters, while speedy middle infielders like Biggio are not.
If one were actually to look at the list of players who have been suspended for performance-enhancing drugs, it might call some of these assumptions into question. Among these players are the utility infielder Neifi Perez, who hit 64 home runs in a 12-year career, the slap-hitting outfielder Jorge Piedra, and a substantial number of pitchers. The incidence of performance-enhancing drug use seems to be fairly randomly distributed between stars and benchwarmers, players at different positions and those with different skills.