We present a joint analysis of Chandra X-ray observations , Bolocam thermal Sunyaev-Zel’dovich ( SZ ) effect observations , Hubble Space Telescope ( HST ) strong lensing data , and HST and Subaru Suprime-Cam weak lensing data . The multiwavelength dataset is used to constrain parametric models for the distribution of dark and baryonic matter in a sample of six massive galaxy clusters selected from the Cluster Lensing And Supernova survey with Hubble ( CLASH ) . For five of the six clusters , the multiwavelength dataset is well described by a relatively simple model that assumes spherical symmetry , hydrostatic equilibrium , and entirely thermal pressure support . The joint analysis yields considerably better constraints on the total mass and concentration of the cluster compared to analysis of any one dataset individually . The subsample of five galaxy clusters is used to place an upper limit on the fraction of pressure support in the intracluster medium ( ICM ) due to nonthermal processes , such as turbulence and bulk flow of the gas . We constrain the nonthermal pressure fraction at r _ { 500 c } to be < 0.11 at 95 \% confidence . This is in tension with state-of-the-art hydrodynamical simulations , which predict a nonthermal pressure fraction of \approx 0.25 at r _ { 500 c } for clusters of similar mass and redshift . This tension may be explained by the sample selection and/or our assumption of spherical symmetry .