We provide another proof of the Sipser--Lautemann Theorem
by which $BPP\subseteq MA$ ($\subseteq PH$).
The current proof is based on strong
results regarding the amplification of $BPP$, due to Zuckerman.
Given these results, the current proof is even simpler than previous ones.
Furthermore, extending the proof leads to two results regarding $MA$:
$MA\subseteq ZPP^NP$ (which seems to be new),
and that two-sided error $MA$ equals $MA$.
Finally, we survey the known facts regarding the fragment of
the polynomial-time hierarchy which contains $MA$.
