Andrew Yang, tech entrepreneur and Democratic presidential candidate, continued his criticism of Joe Biden for missing a campaign in Iowa this past weekend.

“Out of 19 presidential candidates in Iowa this weekend I guarantee you that several were missing family obligations,” Yang said Tuesday after Biden skipped out on an event in Iowa attended by 19 of the other contenders. “That’s what happens when you run for President. If a front runner says that we have different values that’s on him.”