To cut to the chase, the indictments of Donald Trump have not boosted him in the polls, either for favorability or for his support in the GOP primary. This claim keeps being repeated as if the data support it. It does not.

Net favorability nationally

Trump’s net favorability (percent favorable minus percent unfavorable) inched up 1.5-2 points following the first indictment in New York on March 30, 2023, from a median of -14.0 to -12.5, and mean of -14.2 to -12.2. This is the only period of a (slight) improvement compared to the pre-indictment period (Jan. 1 to Mar. 29), Following the Florida indictment the median fell to -18, then -19 after the DC indictment and rose -17.5 after Georgia. (Table of full results below.)

The net favorability is for the national population, so perhaps Trump gained substantially among Republican voters, but not the full population. His support in the GOP primary vote gives us that test.

Trump GOP Primary support

Compared to pre-indictment, Trump did have higher support among Republicans in the primary vote following the New York indictment, a median of 49% prior to the NY indictment and 57% after NY but before Florida. There was no further change after Florida (still 57%), or after DC (still 57%.) After the Georgia indictment the median is 58%. If there was in indictment effect boost at all (see below for why you should doubt that) it was over by the Florida documents case indictment.

The remaining doubt about indictment effects is provided by the trend chart below. Trump’s support for the nomination had been rising steadily since Jan. 1 through the spring. It rose at the same rate following the New York indictment as it had been rising prior to the indictment. The trend levels off in early May, a month after the NY indictment and about a month before the Florida indictment. Since mid-may there has been very little trend in Trump’s primary vote. (Each point in the chart is a national poll and the red line is a local regression trend estimate.) Trump’s margin over DeSantis has continued to climb but that is due entirely to DeSantis’ collapse in the polls, not to any gains by Trump since May. Trump’s current 58% support is more than enough to win the nomination. But it hasn’t been increasing for four months.

There are reports of surges in donations following the indictments. But if so, that hasn’t been reflected in the polling for either favorability or for GOP primary support.

The table below shows the median, mean and number of national polls used in the charts above. Note there are only 4 favorability polls completed between the DC and GA indictments, though there were 16 primary polls in the same interval.

“Indictments help Trump” is folklore that needs to be corrected. There is no polling evidence the indictments help, or hurt, Trump. Any effect of criminal trials remains to be seen.

Reference