My points were that (1) USN does not provide a general ranking of post secondary institutions and that (2) any “T-20” designation can be clear only when associated with a particular source. Nonetheless, since it seems you would like to attend a large institution, with various divisions, rather than a purely undergraduate-focused school, USN’s National Universities list seems appropriate for you.
Irrespective of its categorization, Swarthmore fills its incoming classes with disproportionately brilliant students. Its academic standards and 7% acceptance rate make it inaccessible to most college applicants, however.