MANASSAS, Va. — The voting for Virginia governor on Tuesday, traditionally a referendum on the party in the White House one year into a new administration, is the big political show of 2017.

But the real weather vane for the country may be many rungs down the ballot in obscure races for the House of Delegates.

Amid the turbulence of the Trump presidency, and under a shadow of indictments of former Trump campaign officials, voters heading to the polls in Virginia’s 100 House races represent the purest test of grass-roots anger at the president, election analysts said.

That is because the candidates are little known to voters, largely absent from TV ads, and the races approximate a generic partisan ballot. If the past is a guide, they may also prefigure nationwide congressional voting in 2018.