Billionaire Tom Steyer‘s wife is now chair of his presidential campaign.

Steyer told supporters during an event Sunday night in Yemasse, South Carolina, that his wife, Kat Taylor, had taken the helm of his campaign.

Taylor stepped down from her bank position and rented a home in Columbia, South Carolina, earlier this month to give her an East Coast base of operations as she stepped up her role her husband’s campaign.

Steyer has focused his efforts primarily on Nevada and South Carolina, which holds its primary on Saturday.

The climate activist has spent heavily in the South Carolina, building a massive ground game operation, hiring prominent lawmakers as advisers and garnering support as former Vice President Joe Biden‘s lead tightens. The field participates in a debate Tuesday night in Charleston.