After Republicans expanded their majority in the House of Representatives on Tuesday, giving the party its largest number of seats in the lower chamber since World War II, “Meet the Press” moderator Chuck Todd made an observation that probably triggered even more Democratic heartache.

“So this really secures the House Republican majority for the rest of this decade,” Todd said during NBC’s election coverage. “Not until 2022, I think, at the earliest, will you see Democrats have a chance at winning the House.”

A closer look at the numbers shows why the GOP House majority is basically impenetrable until the next redistricting, and maybe beyond. It was never more stark than in 2012, when Democrats received about 500k more votes nationwide than Republicans but still ended up with substantially fewer seats. Some of this is due to an extremely effective gerrymandering effort by Republicans after the 2010 election. But it’s not only that. Democrats are also increasingly concentrated in small geographical areas, which greatly amplifies the effect of gerrymandering and is also a significant and growing issue in itself.

Here, TPM has taken a look at three states that are among the most populous in the country and that figure prominently in presidential elections. Democratic House candidates in Pennsylvania and Michigan won more votes overall in 2012 but in each state the party ended up with fewer seats than the GOP. In Ohio, Republicans garnered more votes overall in 2012 and 2014; in each year, their percentage of seats won was vastly higher than their share of the vote.

Republicans did better in all three states in 2014, but the distribution of House seats remained the same. And this pattern, if not always to the same degree, shows itself in numerous states.

It’s a good illustration on how virtually unwinnable the current House is for Democrats. As currently constituted, the chamber is relatively immune to big swings in popular opinion and voting support.