Tina Smith built a political career as a behind-the-scenes adviser to some of Minnesota’s most powerful politicians of the last two decades. On Wednesday she joins their ranks, stepping onto the national stage as Gov. Mark Dayton appoints her to the U.S. Senate.

Smith has been Minnesota’s lieutenant governor since 2015, a typically low-profile position that she has elevated on the strength of her close relationship to Dayton. Smith had served as the Democratic governor’s chief of staff and as campaign manager for his successful 2010 gubernatorial bid. She also previously served as chief of staff to Minneapolis Mayor R.T. Rybak. Smith was a top adviser to former Vice President Walter Mondale during his last-minute campaign for the Senate following the death of Paul Wellstone, in 2002.

Smith’s blend of warmth and toughness earned her the nickname “the velvet hammer” at the Capitol. She’s a former marketing executive at General Mills who later formed her own marketing and PR firm, and also served a stint as vice president of public affairs for Planned Parenthood of Minnesota, North Dakota and South Dakota.

As lieutenant governor, Smith has frequently stepped up to serve as the administration’s public face. She has continued to work behind the scenes too, often representing Dayton in budget negotiations with legislative leaders.

Smith, 59, was born in New Mexico but has lived in Minnesota for decades. She and her husband, Archie Smith, live in south Minneapolis; they have two adult sons.