U.S. Sen Amy Klobuchar's revealing new autobiography, book tour and dogged speaking schedule are reigniting talk that she is looking for new political conquests — maybe even an eventual run for the White House.

"People have talked to me about it in the past," Klobuchar said recently in her Minneapolis home. "When someone talks to you about it, you have to think about it in your mind, and I have, but the reason I wrote this book had nothing to do with that."

Klobuchar's rising political profile is burnished by a high approval rating driven partly by strong numbers among independent and Republican voters who see her as a moderate. But it comes at a time when her party's rank-and-file increasingly want bolder, progressive stands from their leaders.

Klobuchar now faces scrutiny from some Democrats who say she does not leverage her enormous popularity enough by pushing harder on major progressive causes, like environmental protections and income inequality.

Rep. Rick Hansen, DFL-St. Paul, praised Klobuchar for her work on invasive carp. But on other issues, he said the "Wellstone wing" of the party, referring to the late Sen. Paul Wellstone, craves more outspoken leadership.

"You need to use the popularity," he said. "You need to remember what you're there for. I think that's where some of the frustration comes in." He contrasted Gov. Mark Dayton's politically risky push for buffers around rivers, streams and ditches to prevent water pollution with one of Klobuchar's votes to limit the Environmental Protection Agency's regulation of some of those same bodies of water.

Klobuchar disputes the idea that she shies away from controversial stands or politically risky issues.

She notes that she was an early supporter of a constitutional amendment on campaign finance reform and recently came out in favor of the Iran nuclear agreement that the White House is still lobbying other senators on. She led the bipartisan effort to lift the Cuban trade embargo; and recently brokered a deal with Republican leaders to combat human trafficking.

Klobuchar says she works hard not to be combative or snarky about opposing sides.

The world "needs rabble rousers," she said, "but you also need to be willing to compromise to get things done."

This strategy, carefully crafted after almost a decade in the U.S. Senate, has obvious benefits.

High approval ratings

The senior senator maintains some of the highest approval ratings of any U.S. senator. A recent survey of 1,015 Minnesota voters found 55 percent approve of her job performance. In one of the most polarized political environments in recent memory, Klobuchar has been lauded widely for working with Republicans. Among senators with more than 10 years of experience, Klobuchar ranks No. 1 for the number of bills co-sponsored, which means she works well across the aisle, according to GovTrack.

In Washington she is seen as a common-sense, hard worker who focuses on "bread and butter" issues, said Jim Manley, a Minnesota native who is now a Democratic strategist after working for 21 years in the U.S. Senate.

"She doesn't get sidetracked by the shiny object du jour," Manley said. "She's one of those people within the caucus who is always pushing the leadership to try and find ways to work with Republicans."

At times, her efforts to keep all options open have backfired.

Klobuchar was among a minority of women senators ahead of the 2008 election who did not endorse Hillary Clinton. She ultimately endorsed then-Sen. Barack Obama — but not until two months after he'd won the state's caucuses by more than 2 to 1.

"Despite Klobuchar's late endorsement of Obama in 2008, Hillary Rodham Clinton and Amy have clearly patched things up," said DFL Chairman Ken Martin.

This time around, Klobuchar didn't wait to throw support behind Clinton, touting the former secretary of state before she even announced she was running. She helped campaign for Clinton in Iowa and has been asked to campaign for her in New Hampshire.

High aspirations

One thing is clear: Klobuchar has high aspirations.

In a memoir that will hit national book stores this week titled "The Senator Next Door," Klobuchar talks about her suburban upbringing and her struggle to break through to the big names in Washington.

"People usually publish books for one of a few reasons," said former Minnesota Gov. Tim Pawlenty. "They want to send a message, or tell an important story, they want to supplement their income … or it's often viewed as a prerequisite to run for higher office."

Mike Berman, a Minnesota native and longtime Democratic adviser and lobbyist in Washington, was more direct.

"She only has a couple of options," Berman said. "She could decide to run for governor. She could continue to move up into the leadership of the Senate. At one time or another, she's talked about even running for president."

Klobuchar rose from Hennepin County prosecutor in 1998, becoming the state's first elected female senator in 2006. She has worked diligently since then to secure her position, visiting every Minnesota county every year. In her 2012 re-election, she won 85 of the state's 87 counties and more than 65 percent of the vote.

But that's not enough for Deanna White, state director of Clean Water Action, who said her group has been trying to get a meeting with Klobuchar since 2008, to no avail.

"I know the excitement people had when she was first elected. I don't think it's been as exciting as people hoped. It's not that she's anti-environmental. But she hasn't shown the leadership we would like," White said of Klobuchar, who must balance the state's strong environmental movement with its influential agribusiness lobby.

Klobuchar also has her champions among the party's progressives.

"I'm from the Wellstone wing of the party, and I'm a fan of hers," said Rep. Frank Hornstein, a seven-term DFLer from Minneapolis. Hornstein noted that Klobuchar "led on Cuba," and praised her efforts with Arizona Republican Sen. Jeff Flake to lift the trade embargo.

"I think the fact she came out on the Iran deal is helpful," Hornstein said. "She's a strong liberal voice, but she has relationships on both sides of the aisle, as [Wellstone] did."

Hard-charging attitude

Klobuchar has developed a reputation for a demanding, hard-charging attitude, and some who have worked for Klobuchar wonder how that would translate to higher office.

She has had six chiefs of staff since 2007. By comparison, Franken has had three since 2009. Missouri Sen. Claire McCaskill, who entered the Senate the same time as Klobuchar, has had one chief this whole time, according to the database Legistorm.

In her book, Klobuchar boasts that she trained herself not to cry when she was the county prosecutor, and writes that she expects a lot from people. "I have high expectations for the people who work for me," she wrote. "I figure that if they work really hard and do a good job on one of my campaigns or in my office, that experience will serve them well later on."

Klobuchar plans a national publicity tour to promote her biography that will include book signings around the state, as well as media appearances in New York.

Asked what is next for Amy Klobuchar, she replied without hesitation: "Well, the State Fair, you know," she said. "Starting tomorrow I'm gonna do 14 more counties."

Allison Sherry • 202-383-6120

Patrick Coolican • 651-925-5042