Editor's note: Our endorsements are based on interviews with the candidates and other research and reporting. The Editorial Board operates independently from the newsroom, and news reporters and editors were not part of the interview process or the decisionmaking. To learn more, go to http://tinyurl.com/m94brmr.

• • •

After unseating incumbent Republican Norm Coleman in a bitter 2008 Senate campaign, satirist-turned-politician Al Franken headed to Washington promising a serious approach to his new career.

We were among the skeptics, in no small part because Franken had zero legislative experience. In fact, this page had endorsed Coleman over Franken and Independence Party candidate Dean Barkley, arguing that in a second term the pragmatic Republican would continue to be a voice of moderation in the party and an effective representative for this politically divided state.

But by a mere 312 recounted votes in a presidential-election-year wave favoring Democrats, Minnesota sent the author of "Rush Limbaugh is a Big Fat Idiot" to the nation's capital.

In an editorial that appeared in this space a day after Franken took the oath of office in 2009, we urged him to make good on his pledge to leave Stuart Smalley behind and focus on policy work that would benefit all Minnesotans.

For the most part Franken has delivered, earning our endorsement for a second term over political newcomer Mike McFadden, an investment banker whose campaign has failed to convince us that Minnesotans should squander the benefits that incumbency can bring.

As we had hoped, Franken is comfortable in "the weeds" — that policy wonk space in which legislators address real-world issues such as student debt, privacy rights and food safety.

"You get the respect of your colleagues if 'you're in the weeds,' " Franken recently told the Star Tribune Editorial Board. "You get the respect of your colleagues because so much of the stuff we can get done has nothing to do with partisan politics."

In a separate interview with the Editorial Board, McFadden described Franken as "the most partisan senator in the Democratic Party," pointing to an analysis by opencongress.org of the 161 votes he took since the beginning of the current session of Congress in 2013. Franken has voted with the Senate Democratic caucus 159 times, for a rate of 98.8 percent — topping the list. But at the same time, Sen. Amy Klobuchar — whom McFadden is quick to praise — voted with her party 96.2 percent of the time (153 of 159 votes).

We find it more meaningful to consider Franken's list of legislative accomplishments since arriving in Washington.

His provision in the Affordable Care Act requiring insurers to spend at least 80 percent of premiums on actual health care is a needed curb on rising administrative costs. Working with Republican Sen. Roger Wicker of Mississippi, Franken co-sponsored legislation targeting credit rating agencies for conflicts of interest that contributed to the 2008 financial meltdown.

He added common-sense provisions to the bipartisan Violence Against Women Act to help protect victims of domestic violence and sexual assault from financial harm. And after 64 people died and hundreds were sickened by tainted medications manufactured by a Massachusetts drug compounding facility, Franken worked with Republican Sen. Pat Roberts of Kansas to reform dated laws on drug distribution.

He has also championed food safety, job training, renewable energy, Internet neutrality, funding for Native American schools, student debt relief and privacy-rights measures.

Minnesota Republicans scoff at Franken's record, arguing that his legislative accomplishments are minor at best. But as Klobuchar has proved, focusing on practical legislation, working hard and serving constituents is a successful formula in Minnesota — especially during a first term.

To his credit, McFadden has run a policy-focused campaign. He faults Franken and his party for their energy policies — including excessive regulation of pipelines and mining — that he says are stifling the economy.

McFadden opposes Obamacare, wants health care regulated by the states, and is a fan of health savings accounts and coverage for those with pre-existing conditions. On Medicare and Social Security, McFadden is short on specifics but pledges to work with members of both parties to address projected funding shortfalls without raising taxes.

He would redirect federal education dollars from "broken school districts" to charter schools — citing the admirable work he's done with Cristo Rey, a Jesuit school in Minneapolis that has had success with low-income students.

McFadden is critical of President Obama's handling of foreign-policy issues but, like Franken, supports the current bombing campaign targeting ISIL. Both candidates want Obama to seek congressional authorization for any escalation of that effort.

McFadden and Franken support overhauling the tax code, but neither offers many specifics. Franken would eliminate subsidies for oil and gas companies, while McFadden wants revenue-neutral "simplicity and transparency."

Conservatives have a clear, credible choice in this race. There's little doubt McFadden would give more critical scrutiny to spending than Franken. He's a quick study and might also have the kind of independent streak that made Coleman our pick in 2008. We're just not sure.

The more we saw of McFadden during the campaign, the more he used Republican talking-point generalities while also pledging to work as a bipartisan problem-solver. He prides himself on not being a professional politician, but he avoids concrete answers to tough questions with the best of them. Without a record to run on, he's asking Minnesotans for trust he has yet to earn in public office.

Throughout his first term, Franken has kept his head down and delivered on what this page asked of him when he belatedly started his term in 2009 — policy work that benefits residents of this state. In many cases, he's done so while working with Republican colleagues.

If he wins re-election, we'd urge Franken to stay in the policy "weeds" but also provide leadership on improving the ACA, seeking the kind of genuine compromise that can produce meaningful progress on Medicare and Social Security, and reforming the tax code.

For the first time, Franken might serve as a member of the minority party, making it even more imperative that he work across the aisle. Based on his record over the past five years, we trust he would take a serious approach to a second term and do exactly that.