Sen. Amy Klobuchar, D-Minn., speaks during the second day of the Democratic National Convention in Philadelphia , Tuesday, July 26, 2016. (AP Photo/J. Scott Applewhite) (The Minnesota Star Tribune)

WASHINGTON – U.S. Sen. Amy Klobuchar will run for re-election in 2018, ruling herself out for Minnesota's next race for governor as she prepares to challenge the new Trump administration and look for ways to work with Republicans leading Congress.

In an interview with the Star Tribune, Klobuchar acknowledged that many DFLers asked her to run for governor instead of Senate re-election. But she said it's not the right time to walk away from Washington.

"I really looked at the moment in history and I feel like my job is there," said Klobuchar, who was first elected in 2006. "The fact that I've been able to get through the gridlock many, many times means that you can't just walk away when it's an ugly time. It means you have a duty and obligation to keep doing your job. It may sound Pollyanna but it's what I decided."

Speculation had swirled for months that Klobuchar, consistently the state's most popular politician, might be ready to switch political jobs. Gov. Mark Dayton won't run again in 2018, and the DFL is desperate to keep a seat he's held for two terms. A former Hennepin County attorney, Klobuchar often says she misses being a chief executive and running a big organization.

Klobuchar's decision throws wide open the upcoming race to succeed Dayton. A number of potential candidates from the DFL and GOP alike were said to be waiting on Klobuchar's decision before finalizing their own plans. Two DFL candidates have already declared a run for the office, St. Paul Mayor Chris Coleman and state Rep. Erin Murphy of St. Paul.

U.S. Senate Democrats benefit from Klobuchar's decision, with a number of incumbents running for re-election in 2018 in states won by President-elect Donald Trump. Klobuchar starts out favored to win another term — Republicans may find it difficult to recruit a big-name challenger — but state Republican Party Chairman Keith Downey said the GOP is ready.

"I think we're going to fight hard and have a real chance no matter what," Downey said. "I don't think there's any daylight between Amy Klobuchar and the now-failed Washington agenda."

Downey said he also expects Republicans to "compete very hard" for governor in 2018. Downey has publicly acknowledged he might even run.

In the next Congress, which starts Jan. 3, Klobuchar secured the top Democratic spot on the Senate Rules Committee. That will give her a voice in changing Senate rules, which will be pivotal as Republicans seek to push Trump's Cabinet nominations and GOP legislative priorities through the upper chamber.

Klobuchar is the second-ranked Democrat on the Agriculture Committee and also serves on the Judiciary Committee, the first stop for Supreme Court nominees and the attorney general nominee.

Calling herself wary of Trump's Cabinet choices so far, Klobuchar said she looks forward to meeting them personally when confirmation hearings start in early January. She specifically mentioned Oklahoma Attorney General Scott Pruitt, Trump's pick to lead the Environmental Protection Agency. He has criticized the Renewable Fuel Standard — a boon for corn growers who produce ethanol.

Data collected by GovTrack ranked Klobuchar the most effective senator in the last congressional session, as measured by 27 bills passed and sent to the president's desk. Her Democratic colleague, Sen. Al Franken, was ranked No. 6 with 22 bills sent to Obama's desk.

Facing a new unity government — a White House and Congress run by Republicans — Klobuchar said she is well-positioned to work on issues that matter, including infrastructure, prescription drug prices and tax reform.

"I just think it's too early to know exactly what he's going to be proposing," she said of Trump. "I also think that there's going to be some key Republicans that will have a lot of influence and I'm close friends with a lot of them."

Republican Sen. Susan Collins of Maine said she and Klobuchar have worked together fruitfully, including on the reopening of the federal government after its two-week shutdown in 2013.

"When Amy is your partner on an issue, your chances of success go up," Collins said. "To be successful, the Democrats need to identify where they can work with the new president and with those of us on the other side of the aisle."

DFL State Chairman Ken Martin said the next two years are extremely uncertain politically. In the past, midterm elections following a political wave in a presidential year usually favored the opposing party. But Trump has thwarted a lot of expectations.

"I think the Republicans, now they own everything in Washington, and they have a lot more power in Minnesota, and because of that they have to govern," Martin said.

Stanley Hubbard, the chairman and CEO of Hubbard Broadcasting and a big Republican donor who has also given money to Klobuchar, said the senator is "smart enough to know the public will."

"Where things make sense I think she'll go along with it," Hubbard said, referring to Trump's agenda and the Republican Congress. "My hope is the Democratic Party will start going more towards the middle. I will happily vote for an Amy Klobuchar or a Harry Truman, but I wouldn't vote for Obama."

Allison Sherry • 202-662-7433

Senator Amy Klobuchar of Minnesota speaks during a press conference with fellow senators Claire McCaskill of Missouri, left, and Mark Warner of Virginia in Havana, Cuba, Tuesday, Feb. 17, 2015. The delegation is in Cuba in support of a bill Klobuchar is sponsoring to lift the U.S. trade embargo on Cuba. According to the senators, a new round of negotiations to restore full diplomatic ties with Cuba will take place next week in Washington. (AP Photo/Desmond Boylan) ORG XMIT: MIN2015021721254877 ORG XMIT: MIN1502271342560071 (Associated Press/The Minnesota Star Tribune)

U.S. Sen. Amy Klobuchar turned down calls urging her to run for governor, saying instead that her experience is need at a pivotal time in Washington. (Star Tribune file photo/The Minnesota Star Tribune)