ROCHESTER - With unmatched popularity in the polls, Democratic U.S. Sen. Amy Klobuchar has barely acknowledged her Republican opponent and has done little to call attention to her re-election campaign.

But Klobuchar, who quickly received overwhelming DFL endorsement Saturday for her re-election bid, is facing an anti-incumbent mood and an uninspired electorate. This time, she'll lack a Democratic wave like the one that washed her into office six years ago.

"No one will outwork us. No one will work harder," Klobuchar told DFL delegates in Rochester.

In her first term, Klobuchar has won plaudits for bipartisan work, but also brickbats from within her party for being too centrist and from Republicans for being too wedded to the Democratic agenda.

For delegates, she posed as someone untainted by her time in Washington, a senator who knows Congress from the inside but ignores the high "fence lines" that separate the left and right.

"I wake up every day inspired by the spirit in Minnesota. Rest assured, even in the wilderness that is Washington, I know that the best way to lead is to follow the North Star," she said in a speech that was more standard campaign fare then inspiring rhetoric.

Republicans say she's just another Washington Democrat. "She's voted for the Reid-Obama agenda lock, stock and barrel," state GOP Party chairman Pat Shortridge said. "They have a lot of account for, when you look at the record in spending, regulation, Obamacare, gas prices, the economy."

In 2006, Shortridge and his campaign team argued that then-U.S. Rep. Mark Kennedy, Klobuchar's GOP challenger, was really independent, even though he voted with Republicans in Congress nearly all the time. Asked about the reversal of argument, Shortridge, Kennedy's campaign manager, said: "How did Mark do in that race, do you recall?" Klobuchar trounced him by more than 20 percentage points.

'No place to go but down'

Klobuchar is promised no repeat blowout.

Although she has more than $5 million already banked, she will battle voters who are sick of Washington phonies, tired of a lagging economy and looking for someone to blame. Sharing a November ticket with President Obama, Klobuchar may be called to account for everything that folks feel has gone wrong.

"Amy's got no place to go but down," former Republican Party chairman Tony Sutton said. "I wouldn't say she is vulnerable yet, but I think she is beatable."

Republicans are backing Kurt Bills, a high school teacher and Ron Paul disciple, for the job. The first-term state representative dismissed the senator as nice enough, but Minnesota, he says, doesn't need a "Miss Congeniality" in Washington, it needs serious change. Bills says he will provide it by closing four federal departments, cutting subsidies to corporate farmers and slashing foreign aid.

Klobuchar's record of working on everyday issues could offer her some inoculation from that call.

Dangerous pools hurting kids? Klobuchar passed a bill to make them safer. Lead in toys? Klobuchar led the way in stepping up the ban. Dangerous synthetic drugs on the market and life-saving cancer drugs unavailable? Klobuchar worked to ban one and free up the other. Traffic on the St. Croix River? Klobuchar partnered with Republican U.S. Rep. Michele Bachmann to make a new bridge happen.

"I think she has done a brilliant job of positioning herself as smart, engaged and in tune with Minnesota," said Norm Ornstein, a congressional scholar at the American Enterprise Institute who happens to be a longtime friend of Democrat Al Franken, Minnesota's other senator.

But recent history could add worry. Although Democrats have been victorious in the last two marquee races, the victories were recount-inducingly thin.

Franken unseated Republican Sen. Norm Coleman by just a few hundred votes in 2008. Gov. Mark Dayton won his 2010 election by a few thousand and he, like Klobuchar, faced a little-known state representative as his opponent.

"I think it is going to be tough, very tough," DFL delegate Mary Kay Walsh-Kaczmarek of Klobuchar's race. She fears Republicans will bring corporate cash into Minnesota to try to defeat Klobuchar .

Attention divided

Even with Klobuchar's endorsement as the convention's highlight, DFLers' attention was pulled away.

Speaker after speaker, including Klobuchar, spoke of the two constitutional amendments on the November ballot. One would ban same-sex marriage; the other would require voters to present photo IDs.

Delegates endorsed resolutions to allow the party to officially work with the campaigns opposing the amendments.

"Maybe the GOP should stop focusing on gay marriage and concentrate on their own marriages first," DFL chair Ken Martin, taking a swipe at former Senate Majority Leader Amy Koch and former Senate staffer Michael Brodkorb, who had an affair. Koch resigned her leadership role after being confronted about the relationship in December.

Martin inveighed against the photo ID amendment, saying it was "an attempt to stifle the democratic process."

The Minnesota DFLers were also pulled to the east.

U.S. Rep. Tim Walz told delegates: "The difference between Wisconsin and Minnesota is Mark Dayton and 8,400 votes." On Tuesday, Wisconsin voters will decide whether to recall Republican Gov. Scott Walker and replace him with a Democrat.

Rachel E. Stassen-Berger • Twitter: @rachelsb