Like losing dirty.
That, I’m afraid, is how millions of Democrats would evaluate the outcome of the midterms if the Republicans hold both houses of Congress while losing the aggregate vote by multiple percentage points. This happened in 2012, when Democrats in House races received nearly 1.5 million more votes than Republicans, with the Republicans nonetheless winning a majority of the seats (by a margin of 234-201). If that happens again, let alone if the discrepancy between the vote and the practical result is even greater, the United States will begin to face a genuine legitimation crisis — with Democrats systematically denied political power commensurate with their level of support in the population at large.
This systematic bias against the Democrats would put them at a political disadvantage across the entirety of the federal government — with the House, the Senate, and the Electoral College all weighted against them, and the judiciary following suit because judges and Supreme Court justices are nominated by presidents and confirmed by the Senate. When this systematic injustice is combined with the GOP’s refusal to govern with the modesty and restraint that befit a minority party, the country would find itself in a highly volatile situation.