I am studying national election campaigns of individual candidates by means of an elite survey (N around 500). Due to the nature of my country case, there are several contextual factors i would like to place special emphasis upon within my IVs. These factors also give the data an hierarchial structure. Candidates in constituencies (over 200) and constituencies in regions (16), that is. Further, candidates are, of course, members of different parties. What i am especially interested in is, whether my DV (some latent variable measuring personalization of the campaign) varies over constituencies and regions and whether the effect of different party memberships on the DV varies over the context factors. My question now is, if a multilevel model would be adequat for investigating these relationships. Naturally there are very low sample sizes on the constituency level, but from what i understood, this should not be a problem for multilevel modelling. Also, how do i link the party with the district/ regional level. By means of interactions?