Richard R. Lau and Gerald M. Pomper, "Negative Campaigning by U.S. Senate Candidates," Party Politics, 7 (January 2001), 69-87.

First Paragraph:
The American electoral process is under attack - not from revolutionaries, but from democratic observers. `Campaign discourse is failing the body politic in the United States', writes a leading analyst (Jamieson, 1992: 11) expressing a fear widely shared. Of particular concern is an asserted increase in negative campaigning, as measured by political advertising (JohnsonCartee and Copeland, 1991; Kaid and Johnston, 1991; Jamieson, 1992; West, 1993; Ansolabehere and Iyengar, 1995; Geer, 1998), and a concomitant decrease in the civility of political campaigns.

Figures and Tables:
Figure 1: Negative Campaigning in US Senate Elections p. 77
Table 1: Who uses negative campaigning? A preliminary look p. 78
Table 2: A multivariate analysis of the use of negative campaigning by US Senate candidates p. 79
Table 3: First-stage regressions predicting use of negative campaigning by opposing candidate p. 82

Last Paragraph:
We can also frankly recognize that there are many instances when we should want candidates to engage in negative campaigning (see also Mayer, 1996). When an incumbent has a poor record in a particular area, shouldn't she be held accountable for it? If a candidate makes a wrong-headed proposal, shouldn't he be taken to task for it? In such instances, criticism of an opponent is a healthy, legitimate part of democratic dialogue. Campaign lies and distortions are unhealthy for democracy and to be discouraged as much as possible, but this adage is equally true whether the liesare aimed at an opponent or used to falsify a candidate's own merits. Better campaigning requires better discourse, however phrased. Our goal should be better politics, not more refined politesse.