| Clue | Source | Date |
|---|---|---|
| Informal surveys | USA Today | 12 Feb 2024 |
| Unofficial surveys | USA Today | 03 Feb 2024 |
| Informal surveys | LA Times Daily | 25 Sep 2023 |
| Unofficial ballots | USA Today | 25 Oct 2021 |
| Informal measures of popularity | New York Times | 22 Jan 2017 |
| Informal measures of popularity | ||
| *Informal surveys | LA Times Daily | 25 Jan 2016 |
| *Informal surveys | ||
| Electoral predictions by the baleful? | The Times Cryptic | 21 Jul 2015 |
| Campaign expenses |