highly significantP < 0.001
In the case of each debate, the difference in assessment between the two groups of supporters was highly significant (χ 2 = 255.52, P < 0.001; χ 2 = 257.28, P < 0.001, respectively), and both groups differed from undecided voters (all χ 2 s > 19.84, P s < 0.001).