Alex Conant, communications director for the Rubio campaign, cited financial concerns, stating, “We are running a lean campaign, so we will only spend money on contests that award delegates.”

Sen. Ted Cruz and Ben Carson are currently the only major candidates who have committed to the event.

Jeb Bush has said that he doesn’t “doesn’t do straw polls,” because of the large financial costs they incur. Money used to buy tickets, meals, and transportation for campaign supporters can instead be used for campaign infrastructure.

Eventual Republican presidential nominees John McCain and Mitt Romney both passed on the straw poll: McCain in 2008 and Romney in 2012.