In the U.S. Senate's DFL special-election primary, one candidate stands above the rest. Chosen to fill the seat of outgoing Sen. Al Franken after he resigned, Tina Smith went to Washington knowing she would have mere months to make an impression on voters, who would then decide whether she deserved the two years left in Franken's term.

Once in office, she quickly displayed what others have long valued in her: a facility for dealing with complex issues, deep knowledge about the levers of government and a no-nonsense attitude about working with all sides to ensure progress.

Smith, 60, has a long track record of public service in this state, mostly unheralded because much of it has been behind the scenes. Her meticulous policy work and coalition-building as chief of staff to Minneapolis Mayor R.T. Rybak helped him shine during his time in office. When the Interstate 35W bridge fell, it was Smith to whom Rybak turned as his point person, working with both the Republican administration of then-Gov. Tim Pawlenty and this state's congressional delegation.

Even though she later managed Rybak's gubernatorial campaign against rival Mark Dayton, when Dayton won he chose Smith to lead his transition and later become his chief of staff. Dayton came to depend heavily on Smith, charging her with leading his administration's efforts on the contentious Minnesota Vikings stadium effort and the complex Destination Medical Center project with the Mayo Clinic in Rochester.

Those years taught Smith a valuable lesson that many politicians have yet to learn: that forgoing the spotlight and focusing on the work often makes it more possible to navigate to "yes." As a senator, Smith has already displayed that same facility, forging relations with Republican colleagues to make progress on expanded mental health services in schools and rural health outreach in the Senate's farm bill.

It should be noted that the Star Tribune Editorial Board disagrees with Smith's support for the recent repeal of the medical-device tax. That tax is a key funding source for the expanded coverage provided through the Affordable Care Act, and no replacement funding has yet been identified. The board also believes that Smith should work to distance herself from her and her husband's stock holdings in some of those same medical-device firms should she win the primary.

As Dayton's lieutenant governor, Smith took on a high profile role, often stepping in for the governor on crucial end-of-session legislative negotiations and leading on a number of administration priorities, including broader preschool, rural broadband, a higher minimum wage and transportation. By 2016, Washington, D.C.'s Roll Call named her one of "America's Top 25 Most Influential Women in State Politics."

In that article, Rybak said of his former chief that she "was able to be tough when she needed to be tough, but she starts most conversations with the idea that people are generally good and want to work together." That kind of pragmatic optimism is what elevates Smith in this primary field and won the Editorial Board's endorsement.

Richard Painter, 56, Smith's leading primary challenger, has chops of his own. The fierce intelligence, commitment and sharp language that made him a frequent commentator on political news shows also have sparked excitement among some Democrats, who see in this former Republican Bush White House ethics lawyer flickers of Bernie Sanders and Franken. But Painter's is an agenda with one item writ far larger than the rest: impeaching President Donald Trump. He is a professor turned firebrand, with a maverick flair that some in the DFL yearn for. But that is not the totality of a U.S. senator's role. Painter's focus on Trump is so intense that it raises concerns about how much attention he would pay to the broad array of issues that Minnesotans need representation on now and in years to come.

DFL primary voters also may want to consider whether they support someone steeped in their values, with a proven track record on their issues, or a newcomer who wants to carry their party's banner while declining to pledge his allegiance to that party. There is room in politics for independent-minded senators, certainly. But primary voters should think carefully about how a prospective senator might vote on an array of issues that stretch far beyond support or opposition to the current administration.

The Editorial Board appreciates the vigor and passion evident in Painter's campaign, but Smith's low-key demeanor and demonstrated ability to work with those who hold varying viewpoints is the better choice for primary voters and the Senate.

Big personalities have become a new and somewhat unfortunate standard lately. The public is enamored of outsized characters who dominate the political landscape, with their no-apologies, no-loaf-is-better-than-half approach. That has produced gridlock, bombast and hard feelings that make progress difficult if not impossible. There should be room in the Senate for quieter voices as well.

"You can go to D.C. and spend all your time trying to score political points, or you can build on common ground," Smith told the Editorial Board. We prefer the latter.

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The other DFL primary candidates are Nick Leonard, Ali Chehem Ali, Gregg Iverson and Christopher Lovell Seymore. The Editorial Board focuses on making endorsements in highly competitive races and chose not to screen candidates in the Republican special primary for U.S. Senate nor in the other DFL Senate primary on the Aug. 14 ballot.