But Palmeiro's ability to look and sound believable no longer matters.
He juiced. And got caught.
That can't be spun, interpreted, denied, avoided or ignored. That's just fact.
To paraphrase Palmeiro's own words: He used steroids - period.
And boy, is he going to be sorry.
If he thinks he can hit his way past the ignominy this will bring him, he's in for a surprise.
This now becomes the second sentence of his career story.
The first sentence is that he spent nearly 20 years compiling offensive numbers that should make him a first-ballot Hall of Fame inductee.
The second sentence is that he was caught using steroids, inevitably casting doubts about how much of his success was legitimate and how much was chemically enhanced.
The Hall of Fame? This could easily knock him out. It's that damaging. Now voters will remember him for being the game's most accomplished certifiable juicer (at least so far) as well as for having that sweet left-handed swing.
Harsh stuff? Sorry, facts are facts. He failed a test.
The best-case scenario for him is that the episode will eventually be viewed like Sammy Sosa's 2003 corked-bat brouhaha - a damaging eye-opener deemed not important enough to undermine his historic accomplishments.
But Palmeiro isn't about to get off that easy.
With the sweeping nature of baseball's steroid crisis becoming clearer every day, a flunked test is becoming one of the darkest, most immutable stains on a player's record, one that raises questions about his very essence and credibility.
Was he a one-time or chronic user? Now you have to wonder.
If he was careless enough to get caught now, in this atmosphere of increased testing and scrutiny, what does that say about his likely habits when there was no testing? Now you have to wonder.
And what about the legitimacy of his numbers? How can you not wonder?