From daylong bus tours to daybreak rallies, Republicans and Democrats are fanning out across Minnesota this weekend in a frenzied final push of an election season that is bound to have major consequences for the state.

Republicans spent Saturday putting miles on their cars and pleading for last-minute dollars in hopes of hardening their control of the Legislature. DFLers knocked on doors and embarked on a bus tour to try to wrestle back control and chart a new course for the state.

Meanwhile, supporters and opponents of proposed constitutional amendments that would limit marriage to heterosexuals and require voters to have an approved ID to cast a ballot were trying to break through to Minnesotans who've not already made up their minds.

The campaign within the state also is taking on new importance at the national level. GOP presidential candidate Mitt Romney is placing a new emphasis on Minnesota. His running mate, Paul Ryan, has made recent visits to the state and plans another Sunday, while independent political groups have unleashed a blizzard of TV ads blasting President Obama. The president, meanwhile, deployed former President Bill Clinton in the state to help nail down its 10 electoral votes, which have been seen as more likely to go the president's way and could prove crucial in a close election.

For both sides, there was little doubt of the importance the election holds for the state and the country. "If you get the DFL majority in the House and Senate, I'll shine your shoes, I'll press your coats, I'll take your exams for you," DFL Gov. Mark Dayton said at a rally last week with Clinton at the University of Minnesota. "I'll do whatever you need me to do."

Final fight over marriage

Topping $16 million in spending by both sides, the battle over the proposed marriage amendment is the most expensive and divisive ballot question in state history.

Staffers from Minnesotans United for All Families were crisscrossing the state in an RV emblazoned with "Vote No" stickers, urging voters to defeat the measure that would have the state Constitution define marriage as between one man and one woman.

"We have three days left to change the course of history," Minnesotans United campaign manager Richard Carlbom told a group in Northfield. "Minnesota is going to be the first state to reject this hurtful amendment," he concluded, referring to the 30 states that have passed similar measures.

Marriage amendment supporters exhibited a calm confidence in the closing days.

They have given away all 60,000 "Vote yes" signs and are focused on their battle-tested formula of reaching out to supporters and to the few voters still wrestling with the issue. Minnesota for Marriage has instructed supportive religious leaders to preach about the issue this weekend, since church congregants make up the largest single block of amendment supporters.

Marriage amendment supporters will make 100,000 calls each day to remind like-minded voters to vote.

"It's important that marriage is between a man and a woman," said Norene Shephard, a retired teacher working at a call center. "This is part of my fabric, my faith and my values. It is the biblical understanding of what marriage is."

Voter ID divides state

The prospect of making permanent changes to Minnesota's election system has driven a wedge through the state.

"I have to do what I can do to make sure my kids' and grandkids' votes are not stolen," Maggie Lizarraga of Mendota Heights said at a pro-photo ID event in Eagan on Saturday.

The proposed amendment would require voters to show a photo ID, set up a new system of two-step provisional voting, end Election Day "vouching" for those without IDs and standardize eligibility verification procedures. The specifics would be filled in by the 2013 Legislature. The two sides see the issue in near-apocalyptic terms.

"This is democracy -- if we lose the right to vote for specific populations of the state, we've lost our democracy," said Carol Gariano, a board member of the anti-ID group TakeAction Minnesota, as volunteers crowded into the group's office last week.

"We have a great system that's working," said Suzanne Durkacs, who serves as an election judge in Minneapolis. "If this thing passes, the electorate is going to shrink."

The many judges who reviewed the Al Franken-Norm Coleman Senate race recount in 2008 may have found no evidence of fraud, but for many ID supporters, it is a matter of belief that Minnesota elections are being stolen.

"I believe that people have fought and died, I believe the right to vote is blood-bought," said Megan Gallup of St. Paul. "And I don't want my vote canceled out by somebody who doesn't exist, has been dead for a year, or is in prison somewhere."

Fight for legislative control

The DFL launched a statewide tour on a bus plastered with the smiling faces of U.S. Sen. Amy Klobuchar, Dayton and Obama. Each stop on its tour is at a state House, Senate or congressional seat the DFL desperately wants to regain.

"It's going to come down to wearing out our shoe leather," DFL Chairman Ken Martin told bleary-eyed volunteers gathered in Red Wing's DFL office early Thursday. Democrats urged Red Wing supporters to make one final push.

"Now we're down to the crunch time," said Democratic congressional candidate Mike Obermueller, who is challenging GOP U.S. Rep. John Kline. "When those volunteers are calling and asking you to take one more shift, you say, 'I'll take two.' When they say, 'Can we get 10 more bucks out of you?' you give 20."

Tilton Davis and Marilyn Tkachuk surveyed the DFL phone-calling and door-knocking board and decided to add another shift. "This is the most important election we've seen in years," Tkachuk said.

Republicans are fighting just as hard. Two years ago, the GOP stunned the state by winning control of the Legislature for the first time in 40 years. Now it is committed to creating a lasting legacy.

"I've tried to portray myself as a common-sense person -- married, a couple of kids. We have the same issues," House candidate Russ Bertsch said while campaigning in Arden Hills. Closely watching is House Speaker Kurt Zellers, whose position relies on candidates like Bertsch winning and the GOP holding the House.

Noting GOP-led reforms of the past couple of years, Zellers said, "I don't think I'm being completely out of my mind in saying those are the very, very first things that would go out."

Battle for Congress

With only three days to go in one of the tightest congressional elections in the state, both candidates in northern Minnesota's Eighth Congressional District got up early Saturday and went hunting.

"It's like a holiday up here," said DFL spokeswoman Megan Jacobs, who is working with challenger Rick Nolan.

Hitting the deer opener is good politics in northern Minnesota. Nolan put on a venison stew feast Friday at his home in Crosby. Republican incumbent Chip Cravaack doubled down on the Second Amendment at a Saturday rally in Duluth with National Rifle Association President David Keene.

Their campaign offices busily dialed supporters. "I want to make a difference," said walk-in Cravaack volunteer Loren Armstrong.

In Duluth, Nolan volunteer Joel Heller and his 5-year-old son, Noah, knocked on 100 doors Saturday morning. "I want the future better for my son," said Heller, a disabled Iraq war vet. "And I think Rick will take care of us vets."

Home-schooled teens gathered in a converted custom motorcycle shop in Blaine on Friday night to make calls for Republican U.S. Rep. Michele Bachmann. "They bring so much enthusiasm," said Sophie Linde, a Duluth native.

Bachmann's DFL challenger, businessman Jim Graves, rallied with volunteers Saturday morning in the parking lot of the St. Cloud Convention Center. Other DFL candidates who joined him, including Klobuchar, worked to fire up the activists. Graves faces a tight but uphill battle against Bachmann, who has raised a U.S. House record $23 million.

Klobuchar, far ahead in the polls against Republican Kurt Bills, emphasized the importance of every vote. She recounted a mid-week trip to unincorporated Tenney, on the North Dakota border, where she found herself talking to the grain elevator operator -- one of the town's last inhabitants.

Staff writers Jim Ragsdale, Kevin Diaz, Jennifer Brooks and Rachel E. Stassen-Berger contributed to this report. Baird Helgeson • 651-925-5044