McGwire, who retired as the No. 5 home run hitter of all-time (he's now 10th), looked like a stone-cold lock for immortality back when he called it a career following the 2001 season. Since then, the question of illegal performance-enhancing drugs in baseball became a front-burner issue, and McGwire was the first true casualty in Hall of Fame voting.
Yet in the past year, McGwire returned as the Cardinals hitting coach. He repeatedly apologized for his use of steroids, and although some argued that he didn't go far enough, McGwire came forward in a way that few of his contemporaries have. Whether that helps or harms his cause remains to be seen.
"Big Mac" was named on 23.5 percent of ballots his first time around, ranking ninth among all candidates. It was more than enough to keep him on the ballot for another year. McGwire's second year on the ballot, 2008, saw virtually the same result. Once again he finished ninth in the balloting. He received 128 votes, or 23.6 percent.
In McGwire's third year as a candidate, his vote total and percentage both dropped, but he bounced back last year. In the 2010 balloting, McGwire once again returned to exactly 128 votes, which this time was good for 23.7 percent of the vote.
A candidate must get 75 percent of the vote to gain election, with former Twins ace Bert Blyleven (74.2 percent) and former second baseman Roberto Alomar (73.7 percent) standing as the top two returning vote-getters.
Before 2010, McGwire admitted taking androstenedione, a steroid precursor, but nothing stiffer than that. In January, though, he stepped forward, admitting to steroid use and apologizing for it. McGwire staunchly continued to maintain that his statistics were not inflated by his use of the drugs, but his contrition was hard to miss.
"I wanted to talk about this five years ago, but I wasn't in position to do it," McGwire said after his nationally-televised apology. "I think everybody that's a human being has held something in that they wanted to release for quite some time. Once they do it, it takes a day or two to really let it sink in, and then you realize that, yeah, it's off my chest. I'm ready to turn the page and move on with my life. It's something that I totally regret. I can't say that I'm sorry enough to everybody in baseball and across America, whoever watches this great game."
As a player, McGwire was a true offensive force and, perhaps, an under-appreciated defender. McGwire was a 12-time All-Star, a Gold Glover in 1990 and finished in the top 10 in MVP balloting five times.
He ranks eighth all-time in slugging percentage, 10th in home runs and first in at-bats per home run. McGwire played on six playoff teams, three pennant winners and the 1989 World Series champion A's.
The career .263 batting average is a negative, but take away the drug use, and it is indisputably a Hall of Fame career.
"For me, there isn't anything that's changed about, No. 1, how much I believe in him, and No. 2, what that means as far as his career and his production and some of the historic things he did," said Tony La Russa, who managed McGwire in both Oakland and St. Louis. "I'm hoping that he gets that honor sooner rather than later.
"I don't know how to tell you the context as far as an answer. I just know there are issues that guys, fans raise, media raise, and however they get sorted out."
When McGwire made his full-season debut in 1987 for a young and emerging Oakland team, he was a phenomenon. He hit 49 homers, most of them mammoth and majestic. He drew 71 walks, showing the strike-zone judgment that would be nearly as much a part of his profile as his power. And he did it in a brutal hitters' ballpark several years before the offensive explosion of the 1990s took hold.
He followed that up with 32, 33 and 39 homers for the pennant-winners from '88 to '90, then struggled badly in 1991. A rebound brought 42 homers in 1992, but McGwire battled injuries throughout '93 and '94.
When McGwire returned healthy in '95, though, he was a force like never before. He hit for a higher average than he had in the past. He drew even more walks. And he hit homers at a rate even he hadn't previously managed. From 1995 through 2000, his last really effective season, McGwire went deep 316 times, an average of once every 8.06 at-bats.
McGwire was a terrorizing force in the lineup until injuries finally took him down. He struggled through 2001 before hanging it up at age 38.
Now, McGwire's Hall's candidacy has a new context. If he experiences a surge forward this year, it may well be an indication that his long-term chances are once again legitimate. If even his 2010 apology didn't do the trick, McGwire's Cooperstown odds will look very long indeed.