and only a theory:
B. Writer of presidential bios, like all writers, needs publicity and royalties.
I. Writer does an appraisal of trendy subjects.
N. Writer finds suitable trendy subject: gay issues.
G. Writer looks at surveys of popular presidents.
O. Writer finds a popular president who’s dead, and whose descendants aren’t likely to sue: Lincoln.
Writer does math: Popular, dead president + trendy subject = BINGO
I’m such a cynic.