Billionaire activist and 2020 Democrat Tom Steyer pledged to push for a $22 minimum wage if he wins the White House in November.

Steyer made the pledge while campaigning in Winnsboro, South Carolina, on Sunday. His minimum wage standard is the highest so far of the Democratic presidential primary field.

The federal minimum wage has sat at $7.25 for the past decade. Washington, D.C., and 29 states have set higher standards, however.

Steyer’s wage floor is set much higher than what most politicians and activists are currently calling for. Former Vice President Joe Biden, former South Bend, Indiana, Mayor Pete Buttigieg, Sen. Bernie Sanders of Vermont, and Sen. Elizabeth Warren of Massachusetts have all released plans calling for a $15 minimum wage.

In July, almost all Democrats and three Republicans in the House voted to double the minimum wage to $15 an hour. A Congressional Budget Office assessment of the impact of a $15 minimum wage estimated that the House-passed bill would increase wages for about 37 million people while putting up to 3.7 million people out of work.

The union-backed Fight for $15 movement is pushing for a $15 minimum wage for fast-food restaurant workers.