We could have ourselves a developing situation here.
The Hall's website, in their election story, says that there were 571 ballots sent out. Craig Biggio got 427 votes, which results in being two votes shy of the 75% needed for election into the Hall of Fame. However, in the table to the right of the linked story, there were 569 ballots cast. With the help of our BBWAA-branded abacus, we can determine that 427 divided by 569 is 75.04%...which would mean Biggio is in.
Rule 4c says:
Any candidate receiving votes on seventy-five percent (75%) of the
ballots cast shall be elected to membership in the National Baseball
Hall of Fame.
We're checking this out as I type...
UPDATE: The Hall has updated the table to the right of the above link to show 571 ballots cast. So Biggio is still two votes shy. That would have been fun, though.
Feel free to check the list of Jacknuts - that we know of - who did not vote for Craig Biggio.