This research explores how message style influences persuasion in conjunction with message substance. Using the elaboration likelihood model, the study operationalizes message style as language power and message substance as argument quality, then considers the multiple roles language power can assume in persuasion. The authors investigate whether language power acts as a (a) central argument, (b) peripheral cue, (c) biasing influence on assessment of arguments, or (d) distraction that inhibits argument processing. Additionally, they manipulate exposure time to examine how processing ability influences which persuasive roles language power assumes. The authors find empirical support for the multiple-roles perspective and conclude that the role of message style depends partially on the ability to process message details.