The DFL Party endorsement for an open Fifth Congressional District seat would ordinarily bestow considerable advantage on its recipient. But there’s not much that’s ordinary about the CD5 contest this summer or about the party endorsement that was won Sunday by state Rep. Ilhan Omar of Minneapolis.

Residents of Minneapolis and several western suburbs learned on June 5 that Keith Ellison, their U.S. representative for the past dozen years, would not seek re-election this year. He’s running instead to be Minnesota’s attorney general, a post being vacated by DFLer Lori Swanson, who is running for governor.

That set off a 10-week sprint that saw first eight, then six and now five DFLers in active pursuit of the seat. The district’s strong DFL voting history suggests that a win in the Aug. 14 primary will be tantamount to election.

If another pattern prevails, primary voters will be making a choice with long-lasting consequences. The Fifth District has been represented by only four U.S. House members — Walter Judd, Don Fraser, Martin Sabo and Keith Ellison — in the past 76 years.

That means that for the Fifth District, an uncommonly consequential election lies just eight weeks ahead — and it’s a primary, which in the last five years is an election that has produced an average statewide turnout of just under 11 percent.

For the sake of their next representative’s democratic legitimacy, the district’s voters should be aiming to beat that turnout average by a substantial margin. They should plan early to vote either on Aug. 14 or earlier via Minnesota’s “no excuses” absentee voting process. They should have already begun to familiarize themselves with the candidates and the issues.

It’s understandable that the district’s dominant political party would want a hand in selecting a candidate. But DFL activists had no opportunity to make an endorsement before the filing period ended and no carrot or stick big enough to compel candidates to either compete in Sunday’s “special convention” or abide by its decision. Three of the five DFL contenders for the seat sought endorsement. None will end his or her campaign as a result of Omar’s second-ballot win.

That does not mean that the party’s endorsement lacks political value. But it’s not the decisive word. It’s one of many factors for Fifth District voters to consider as they compare Omar with the others in the race: former House Speaker Margaret Anderson Kelliher, state Sen. Patricia Torres Ray, DFL Somali Caucus founder Jamal Abdulahi and real estate broker Frank Drake (the 2016 Republican candidate for the seat).

Even for ordinary campaigns in ordinary years, Minnesota’s candidate selection system rests the final responsibility for vetting a party’s candidates with primary voters rather than convention delegates. In the extraordinary circumstances this year in the Fifth, that’s still true — only more so.