query on a TIGER states table (Imported from Census SHAPE using shp2pgsql) to generate GeoJSON for each that osmium will understand.

query-states-geojson.sql

COPY (
    SELECT name, jsonb_build_object(
        'type',        'Feature',
        'id',          gid,
        'geometry',    ST_AsGeoJSON(geom)::jsonb,
        'properties',  to_jsonb(row) - 'gid' - 'geom')
    FROM (SELECT * FROM cb_2016_us_state_500k) row)
TO '/Users/martijnv/osm/planet/states.tsv';