  In a general two Higgs doublet model, we study flavor changing neutral Higgs
(FCNH) decays into leptons at hadron colliders, $pp \to \phi^0 \to
\tau^\mp\mu^\pm +X$, where $\phi^0$ could be a CP-even scalar ($h^0$, $H^0$) or
a CP-odd pseudoscalar ($A^0$). The light Higgs boson $h^0$ is found to resemble
closely the Standard Model Higgs boson at the Large Hadron Collider. In the
alignment limit of $\cos(\beta-\alpha) \cong 0$ for $h^0$--$H^0$ mixing, FCNH
couplings of $h^0$ are naturally suppressed, but such couplings of the heavier
$H^0, A^0$ are sustained by $\sin(\beta-\alpha) \simeq 1$. We evaluate physics
backgrounds from dominant processes with realistic acceptance cuts and tagging
efficiencies. We find promising results for $\sqrt{s} = 14$ TeV, which we
extend further to $\sqrt{s} = 27$ TeV and 100 TeV future pp colliders.
