Gov. Mark Dayton upended the dynamics in the race for governor Tuesday, selecting chief of staff Tina Smith to be his running mate as the DFLer begins his campaign for a second term.

In making his pick, Dayton has chosen a steady dealmaker who has quietly emerged as the most powerful and well-connected force in the administration.

“Tina is the best administrator with whom I have ever worked,” Dayton said Tuesday to a standing-room-only political rally at the St. Paul headquarters of the AFL-CIO, one of the state’s largest unions. “She has the exceptional ability to get people working together to make things happen.”

Smith was Dayton’s point person for some of the most complex, high-profile and politically dicey development projects of Dayton’s term. She took a leading role in the effort to build a new Vikings stadium and a multibillion-dollar, state-backed expansion of Mayo Clinic in Rochester.

A figure in local politics for years, Smith has gained a reputation for being approachable, likable — but with tough, get-it-done edge. In her earlier job as chief of staff to Minneapolis Mayor R.T. Rybak, she was known as the “velvet hammer.”

Smith has run political campaigns and offices but has never faced ­voters on her own. Now she will start close to the top, becoming Dayton’s chief surrogate in what is expected to be a fierce fight for re-election. At 55, Smith is more than a decade younger than the governor and is expected to bring a jolt of energy to the ticket.

On Tuesday, she fired up the crowd on an issue close to many: “Our work is not done. … Are we going to raise the minimum wage?” she said to cheers from union members.

GOP blasts ticket’s urban slant

Republicans were already taking aim at the ticket’s urban slant, amplifying earlier GOP criticism that the administration has shortchanged rural Minnesotans to benefit the Twin ­Cities. Smith lives near Lake Harriet in south Minneapolis. Dayton lived in the Minneapolis area for much of his life.

“Mark Dayton has turned his back on the nearly 5 million Minnesotans who don’t live in the City of Lakes,” said Ben Golnik, chairman of the Minnesota Jobs Coalition, a group trying to defeat Dayton and elect Republicans to the Legislature. “Dayton doubled down on his incompetence by picking a current staffer and longtime DFL insider.”

Dayton’s campaign rejected the notion of any metro-area bias, saying the evidence shows the administration has improved lives across the state.

“Governor Dayton has been representing all Minnesotans for his entire public service,” Smith said.

Smith will step into her new role almost immediately. She resigns her position this week and heads out to travel the state as the campaign gets underway.

Smith’s presence on the campaign trail comes at an opportune time for Dayton. The governor is scheduled for surgery at Mayo Clinic next week to reattach tendons in his hip, which he injured in a fall at his residence last year. Dayton, 67, will take several days to recuperate but could have to wear a brace for up to six weeks, which could restrict his ability to campaign.

Current Lt. Gov. Yvonne Prettner Solon, who late last month said she would not run for re-election, will continue to carry out the duties of her office through the end of the year.

Prettner Solon helped Dayton through a competitive primary in 2010, with strong ties to Duluth and the Iron Range. Smith offers no geographic advantage but brings a different set of attributes expected to shake up the race.

A former vice president for Planned Parenthood of Minnesota, North Dakota and South Dakota, Smith has long, deep DFL connections that range from grass-roots activists to mega-donors. Smith, who has an MBA and once worked for General Mills, also has strong ties to many Minnesota business leaders.

Those business connections may blunt what is expected to be strong support from the business community for the eventual GOP nominee.

Charlie Weaver, executive director of the Minnesota Business Partnership and a former chief of staff to Republican Gov. Tim Pawlenty, called Smith’s selection a positive step for the administration.

“She is smart, respected and most important — has the confidence and trust of the governor,” said Weaver, whose group helped coordinate a multimillion-dollar effort to try to defeat Dayton in the last election. “She would have the capacity to make the lieutenant governor’s office relevant.”

Republicans will have their own primary battle before figuring out who faces off against Dayton, but the field has already started zeroing in on the governor’s perceived vulnerabilities, like the fumbled rollout of MNsure, the state’s health insurance exchange.

“Dayton’s policies, supported by Smith, have brought higher taxes, more wasteful government spending, and forced hundreds of thousands of Minnesotans to scramble to keep their health insurance policies,” said former House Speaker Kurt Zellers, R-Maple Grove.

Opponents turned allies

Dayton and Smith have not always been on the same side.

In 2010, Smith led the gubernatorial campaign for Rybak, who was locked in a heated battle with Dayton and DFLers. An old hand at convention fights, Smith was among a ­cluster of campaign managers and party leaders who denied Dayton the pass that kept him off the DFL convention floor after he refused to abide by party ­endorsement.

Smith also is a longtime friend of Dayton’s former wife, Alida Messinger, a significant donor to Dayton’s first election effort and other ­prominent DFL causes.

When Dayton searched for someone to help his campaign after ­winning the DFL primary, Messinger recommended Smith for the job.

Since then, Dayton and Smith forged a strong relationship as they worked through some of the toughest issues of his term.

Several people close to the administration said more than any political calculation, Dayton wanted someone loyal and who he trusted. That put Smith at the top of the list.

Smith is one of the few people in the administration who jokes openly about her boss, a leader with a reputation for being demanding, impatient and critical.

“I have spent a lot of time talking to people over the last several years, talking to them about what the governor is all about,” she said. “I am exciting to spend more time doing that … It’s going to be fun.”