These groups converge in a space of possible attitudes in a classic application of rational choice theory to them by Anthony Downs. Divisions in (-5[1])Western Europe in the late 1800s set these groups in “frozen”equilibrium according to a 1967 essay by Lipset and Rokkan. Campbell et al.’s Michigan Model proposed that attachment to these groups transmits strongly across generations (15[1])and pioneered the study of (*) “identification” with them. Systems of these linkage groups form along divisions like “center versus periphery”according to cleavage theory. The shift of one of these organizations to a “big tent” in 1932 is a classic example of realignment. For (10[2])10 points, Canada’s NDP is an example of what organizations that run candidates in elections? ■END■