Iowa Gov. Kim Reynolds is expected to endorse Florida Gov. Ron DeSantis at a Monday rally, according to a person familiar with the arrangement and granted anonymity to speak freely.

DeSantis had long been expected to win the popular governor’s endorsement, and the two have been campaigning together extensively in Iowa, which will host the GOP’s first presidential nominating contest in January.

DeSantis is trailing former President Donald Trump by significant margins, according to polls, and hopes the endorsement will give him a boost as the race heads into the final stretch.