Nate Silver's Silver Bulletin reported its generic ballot average easing to D+6.1 on Tuesday 30 June, down from the D+6.9 high it reached in late May1. The generic ballot asks voters which party they would back for Congress, and it remains the most-cited single indicator of the national midterm mood. A late-June reading had already put the split at eight points as Trump's economic approval touched a record low; the slight easing since leaves the Democratic lead broad but no longer at its peak.
A lead of this size still points to sizeable Republican losses on a neutral map, which is why the party's redistricting and campaign-finance manoeuvres matter so much to holding the House. A drift of under a point in a single month sits within normal polling noise, so the figure to watch is whether the easing continues into the autumn rather than this one reading.
