Workers attach a Kansas state sign to a microphone pole inside the Wells Fargo Center ahead of the Democratic National Convention in Philadelphia on July 24. (David Paul Morris/Bloomberg)

After President George W. Bush won reelection in 2004, there was a rumbling that the Republican Party had permanently broken the back of its opponents. Bush was underwater in his approval rating before the election, and his administration was hobbled by a slew of problems. But he won, convincingly — as did a majority of Republican House and Senate candidates. Bush started his second term with big majorities on both sides of the Hill.

Two years later, it was over. The Democrats retook the House and split the Senate. Two years after that, the Senate was in Democratic hands and Barack Obama was elected president. Over four years, the Republican lock had become a Democratic rout.

The picture was the same at the state level, as we noted in 2015. That blue bump right before 2010 was the turnaround.

But that graph shows what happened next: The bottom fell out. Not only did the Democrats give up their gains in state legislatures, they hit a new low.

The problem wasn’t just an electoral one. Gallup polling showed Americans in nearly every state identifying more heavily as Republican.

The only state between 2008 and 2014 in which people were less likely to identify as Republican? Alaska.

Last weekend’s election of former labor secretary Tom Perez to lead the Democratic Party put a new highlight on this crisis on the left. The question trickles out from 1600 Pennsylvania Avenue: How do you win the White House, how do you win the Hill, how do you win the state legislatures? In recent years, Democrats have been disadvantaged by lower turnout rates among their voters. The fact that some states hold legislative elections in off-years — 2011, 2013, 2015 — seems as though it may make that problem even worse.

Consider Virginia, for example.

Virginia’s legislature is much more Republican than its presidential votes, according to data from the National Conference of State Legislatures. Virginia holds off-year elections and is one of three states that has a majority Republican legislature after the 2016 elections despite voting for the Democratic candidate for president. (The other two are Minnesota and New Hampshire; there are no states that backed the Republican in 2016 but have a Democratic legislature.)

Since 2008, nearly every state saw its presidential vote and its legislature move to the right.

Two states, California and Arizona, grew more Democratic on both counts. Seven others split, mostly thanks to five that voted more heavily Democratic in the presidential race (like Georgia, Utah and Texas). Every other state, 40 of them, became more Republican. (This data excludes Nebraska, which has a nonpartisan legislature.)

Some states, like Arkansas and West Virginia, shifted dramatically over that time. You can see each state below.

The question for Democrats is a simple one. Is this a permanent shift to the right, or is it low-water mark? There’s one sign of optimism they can cling to: In Delaware over the weekend, a special election for state Senate yielded an overwhelming victory for the party, at a wider margin than was expected. Why? In part, observers credit the swing to the Republicans in November and the polarizing nature of President Trump.

Politics is cyclical, and the Democrats are out of cycle. There’s no guarantee that the states on that map above will start flickering more blue — but there was no guarantee in 2004 that they were going to stay red, either.