  Light-front field theory offers a scenario in which a constituent picture of
hadrons may arise, but only if cutoffs that violate explicit covariance and
gauge invariance are used. The perturbative renormalization group can be used
to approximate the cutoff QCD hamiltonian, and even at lowest orders the
resultant hamiltonian displays interesting phenomenological features. A general
scheme for computing and using these hamiltonians is discussed and it is
explicitly shown that a confining interaction appears when the hamiltonian is
computed to second order.
