200+ years ago when u.s. was 'founded' small-d (generally egalitarian) democrats understood political significance of jury trial, they argued for it as one means of effective popular control, don't recall where (may have been h. aptheker, is one not supposed to go there these days), but I've read that there was great enthusiasm for jury service at the time...
of course, u.s. juries have historically underrepresented minorities, women, young, low-income because of ways that jury pools have been derived via voter registration records, county tax rolls, residency lists...
not surprisingly, evidence indicates that juries comprised of middle-strata "cross-section" tend to be unsympathetic to low income defendents...
In response (in part at least) to criticism of biased character of juries, number of US states now use driver's licenses to select prospective jurors (which may underrepresent older persons and many who live in urban areas sans licenses).
It has only been since 1986 u.s. supreme court decision in *batson v kentucky* that prosecutors have been prohibited from using peremptory challenges (potential jurors rejected "without cause") to exclude based on race., and only since 1994 s.c. ruling in *j.e.b.v alabama* with respect to gender...
some states have reduced jury size from 12 to 6 or 8 persons and evidence indicates that smaller size increases exclusion of minorities...
for working people, per diem that jurors receive is less than already low pay that many cannot afford to but will lose during their jury time...
in actuality, there are fewer u.s. jury trials than might be assumed, in some jurisdictions, as many as 90% charged with criminal felony offenses plead guilty (usually through plea bargain), of those who go to trial, about 50% opt to have case heard by judge rather than jury... michael hoover