Complex sentence: Clinton supporters regarded Hale's allegations as questionable, as Hale had not mentioned Clinton in reference to this loan during the original FBI investigation of Madison Guaranty in 1989; only after coming under indictment for this in 1993 did Hale make allegations against the Clintons.
Split into simpler sentences: Clinton supporters regarded Hale's allegations as questionable, as Hale had not mentioned Clinton in reference to this loan during the original FBI investigation of Madison Guaranty in 1989. Only after coming under indictment for this in 1993 did Hale make allegations against the Clintons.