On the last day of their convention in Bloomington, hundreds of union delegates waited patiently for keynote speaker Gov. Mark Dayton to arrive.

When he did, the welcome was raucous. Delegates to the American Federation of State, Municipal and County Employees annual meeting two Saturdays ago erupted in cheers and rose to their feet, clamoring to shake the DFL governor's hand and pose for pictures as Dayton made his way to the podium.

The Democratic incumbent, in the middle of his first re-election effort, did not disappoint them, delivering a fiery address in which he ticked off his signature accomplishments: a tax hike on Minnesota's wealthiest to balance the state's budget, a minimum-wage increase indexed to inflation and an expansion of collective bargaining rights that could yield thousands of new members.

"Without you, I would not be here today," Dayton said, before asking the crowd for its support one more time.

Unions were crucial in propelling Dayton past his two DFL opponents in the 2010 primary election, few more so than AFSCME Council 5, whose more than 40,000 members make it the largest public-sector union in the state. Since taking office, the former U.S. senator and state auditor has emerged as the most labor-friendly governor Minnesota has seen in decades.

The distinction is particularly notable in an era of declining head count and political power for unions nationwide, including next door in Wisconsin, where Republican Gov. Scott Walker led a heated fight to strip public-sector employees of their collective bargaining rights.

GOP's Johnson critical

Dayton's GOP opponent, Jeff Johnson, says Dayton has gone overboard, citing the governor's efforts to pave the way for a unionization vote last month that affected 27,000 home health care aides. A parallel unionization effort is underway for Minnesota child care workers, who would organize under AFSCME.

A Hennepin County commissioner, Johnson says he supports "right-to-work" legislation that bars unions from requiring employees to pay dues, even if they are covered by a union contract — a restriction that typically diminishes the power of unions in such states.

The GOP challenger said recently that if he were governor, he would push to repeal the legislation that allowed child care and home health care workers to decide whether to unionize. "I would certainly try," Johnson said at a recent news conference. "It would be hard to reverse, but not impossible."

In an interview with the Star Tribune, Dayton said of his union support that "I'm certainly aware to the degree various parts of labor support what I'm doing, but I don't look at my record through the lens of 'How did that serve the needs of labor?' It's how does it serve the needs of Minnesota."

$150,000 toward re-election

Labor unions are determined not to let the recent momentum in Minnesota stall, especially considering that before Dayton, it had been two decades since a Democrat served as governor. Should Dayton get re-elected, unions say they will pursue a new goal: paid sick leave — not for union workers, most of whom have such a benefit, but for workers across the state.

Dayton says he would need to study the particulars of any new bill, but said of the sick leave proposal that to "penalize somebody financially because they get sick, to me is not a good business practice."

Labor union political action committees have already sent $150,000 to Dayton's re-election effort, according to the most recent election filings data.

Unions also have pumped more than $4 million to boost Democrats up and down the ticket. The Minnesota DFL House political arm has received $1.4 million to help Democrats keep their hold on the governor's office and the House, where Democrats have held the majority since 2012.

"When AFSCME gets behind a candidate, we take it very seriously," said Elliot Seide, AFSCME Council 5 executive director.

Seide said his members will hit the ground in coming weeks, door-knocking and calling potential voters to make the case for a Dayton second term. New in their arsenal this year: thousands of members of retiree chapters "with time on their hands," Seide said, and a willingness to churn out phone calls.

Seide said that the efforts by Dayton and unions have benefited working-class Minnesotans across the board. He points to the start of all-day kindergarten and a new law that requires state contractors to pay women equal wages, along with other workplace protections.

The strategy by labor unions advocating for higher minimum wage laws, sick leave and other policies is part of a broader national effort to make labor groups more inclusive and to stem the criticism that public employee unions now enjoy better benefits than private sector workers.

Right to organize

Dayton, answering critics such as Johnson who accuse him of "payback" to unions, said there is no quid pro quo between him and any union group. He said he supports the right to organize and collectively bargain because he considers it an effective way to build a stronger middle class. He also defends his approval of a measure that allowed for home health care workers to vote on joining a union, saying that workers should have that option.

Business groups have said that Dayton's policies could actually hurt workers because minimum wage increases might cause layoffs, while unionization of child care and health workers could increase costs and hurt independent child care operators who consider themselves small businesses and who don't necessarily want to be represented by a union.

Relations laborious at times

Dayton hasn't always had the union support he enjoys now.

Amid the fiercely contested DFL gubernatorial primary of 2010, Dayton, himself a former teacher, saw two of the state's more powerful unions — Education Minnesota, which represents 70,000 educators, and the Minnesota Nurses Association — first choose his rival, then House Speaker Margaret Anderson Kelliher. The unions later moved to his side after he won the primary.

Dayton rankled the teachers union in 2011 by signing a measure that approved alternative teaching licensures for mid-career professionals.

Peter Rachleff, a labor historian at Macalester College, said that Dayton's policies have been aimed at building an infrastructure that provides stability for the working class.

"He's been pro-worker more than what people typically mean when they say pro-labor," Rachleff said.

Star Tribune staff writer Glenn Howatt contributed to this report. Ricardo Lopez • 651-925-5042