In this talk, we give an overview of Seymour's matroid decomposition theory in the context of binary linear codes, and discuss some of its implications for linear programming (LP) decoding of a binary linear code. Given the formulation by Feldman \emph{et al.} of maximum-likelihood (ML) decoding over a discrete memoryless channel as an LP problem, we translate matroid-theoretic results of Gr\"otschel and Truemper from the combinatorial optimization literature as examples of non-trivial families of codes for which ML decoding can be implemented in time polynomial in the length of the code. One such family is that consisting of codes $C$ for which the codeword polytope is identical to the Koetter-Vontobel fundamental polytope derived from the entire dual code $C^\perp$. However, we also show that such families of codes are not good in a coding-theoretic sense --- either their dimension or their minimum distance must grow sub-linearly with codelength.