Walter Shapiro @MrWalterShapiro
A significant factor in candidates dropping out during odd-numbered years was the GOP's Iowa Straw Poll. An expensive event, it drove out candidates like Pawlenty (2011) and Lamar! (1999). The Democrats, to their credit, haven't encouraged straw polls since the 1980s. — PolitiTweet.org
FiveThirtyEight @FiveThirtyEight
On average, about 1 out of every 4 candidates have dropped out before the Iowa caucuses. https://t.co/eVpT6BqFGK https://t.co/S69wBrKcgm