The road from Kalamazoo to Congress is long

SEAN McCann, a state senator from Kalamazoo, leads in the Democratic primary in Michigan's 4th congressional district. He faced only one opponent, Diop Harris II. The result was never much in doubt: Mr McCann holds the governor's endorsement and a legislative résumé stretching back to 2010. What matters is what comes next. He now faces Bill Huizenga, the Republican incumbent who has represented southwest Michigan in Congress since 2011 and won last year's election by 12 points.

Mr McCann's primary lead tells you almost nothing about his chances in November. Primaries are fought on a low-turnout, ideologically skewed electorate; general elections are won over a broad coalition that includes independents, suburban moderates and rural Republicans. The primary is a formality. The general election is the test.

That test is a difficult one. Michigan's 4th district, which covers all of Allegan and Van Buren counties and parts of Ottawa, Kalamazoo, Calhoun and Berrien, is rated R+3 by the Cook Political Report and labelled Lean Republican. Donald Trump carried the district 52% to 46% last year; Mr Huizenga won 55.1% to 43.4% against Democrat Jessica Swartz. The district is 63% rural, with a median household income of about $74,700 and a population that is 75% white. It voted for Mitt Romney over Barack Obama in 2012 and for Trump in both 2016 and 2020. None of these facts is new, but they establish the terrain Mr McCann must cross.

He brings some advantages. Mr McCann has spent his career in Michigan politics: city commissioner, state representative and state senator. He co-authored legislation to end gerryandering in Michigan and helped establish an independent citizens redistricting commission, which gives him a credibility edge on governance issues. He has sponsored gun-violence prevention measures, including universal background checks and safe-storage requirements, and earned the endorsement of the Giffords law-centre, a firearms-reform group. His record is establishment, not insurgent. In a district that leans Republican, that may be a feature rather than a bug. Voters in competitive areas tend to prefer familiar, moderate faces over activists.

To be sure, Mr Huizenga is not an invincible incumbent. His last victory, at 55%, was solid but not commanding in a district where Republicans normally win by larger margins in down-ballot races.

The real question is whether the district's Republican gravity can be overcome. A seat rated Lean Republican requires more than a competent Democratic nominee. It needs a strong national wave, a dispiriting incumbent, or both. The Democratic Senate primary in Michigan - between Rep Haley Stevens and Abdul El-Sayed, a progressive standard-bearer - will tell you something about whether the national party is cohering in a state it needs to defend. A chaotic Democratic cycle could depress turnout and benefit Republicans in down-ballot races even in competitive areas.

Mr McCann's path is not impossible. Incumbents in lean-red seats have been flipped in recent cycles: the Midwest has proved more volatile than its partisan indices suggest. But flipping a district where the presidential candidate lost by six points and the incumbent won by 12 requires a wave of at least that magnitude, plus an appealing nominee who can hold rural counties from further decline while mining suburban and college-town counties for every available vote. Mr McCann's moderation and institutional experience may help with the former. Whether they suffice for the latter is the question the November election will answer.

For now, the primary is merely the opening frame of a longer contest. Mr McCann has cleared the first hurdle. The rest of the track is uphill.