  We prove a variety of results on the existence of automorphic Galois
representations lifting a residual automorphic Galois representation. We prove
a result on the structure of deformation rings of local Galois representations,
and deduce from this and the method of Khare and Wintenberger a result on the
existence of modular lifts of specified type for Galois representations
corresponding to Hilbert modular forms of parallel weight 2. We discuss some
conjectures on the weights of $n$-dimensional mod $p$ Galois representations.
Finally, we use recent work of Taylor to prove level raising and lowering
results for $n$-dimensional automorphic Galois representations.
