  Rapid and luminous flares of non-thermal radiation observed in blazars
require an efficient mechanism of energy dissipation and particle acceleration
in relativistic active galactic nuclei (AGN) jets. Particle acceleration in
relativistic magnetic reconnection is being actively studied by kinetic
numerical simulations. Relativistic reconnection produces hard power-law
electron energy distributions N(gamma) = N_0 gamma^(-p) exp(-gamma/gamma_max)
with index p -> 1 and exponential cut-off Lorentz factor gamma_max ~ sigma in
the limit of magnetization sigma = B^2/(4 pi w) >> 1 (where w is the
relativistic enthalpy density). Reconnection in electron-proton plasma can
additionally boost gamma_max by the mass ratio m_p/m_e. Hence, in order to
accelerate particles to gamma_max ~ 10^6 in the case of BL Lacs, reconnection
should proceed in plasma of very high magnetization sigma_max >~ 10^3. On the
other hand, moderate mean jet magnetization values are required for magnetic
bulk acceleration of relativistic jets, sigma_mean ~ Gamma_j <~ 20 (where
Gamma_j is the jet bulk Lorentz factor). I propose that the systematic
dependence of gamma_max on blazar luminosity class -- the blazar sequence --
may result from a systematic trend in sigma_max due to homogeneous loading of
leptons by pair creation regulated by the energy density of high-energy
external radiation fields. At the same time, relativistic AGN jets should be
highly inhomogeneous due to filamentary loading of protons, which should
determine the value of sigma_mean roughly independently of the blazar class.
