The Washington PostDemocracy Dies in Darkness

Barack Obama isn’t on the ballot in 2014. But he pretty much is.

US President Barack Obama makes a statement on the situation in Iraq at Martha's Vineyard, Massachusetts, on August 11, 2014. AFP PHOTO/Nicholas KAMMNICHOLAS KAMM/AFP/Getty Images

President Obama's unpopularity isn't getting worse or better. It just is.

Obama's approval rating are not budging from the low 40s, despite numerous political events this year have threatened to boost or damage his standing. And while the stability is certainly preferable for him to 2013's consistent declines, his stubborn negative ratings are also pretty clearly hurting Democrats. That's because we live in an increasingly polarized and nationalized electorate.

In Gallup's tracking wave completed Sunday, 42 percent approved of Obama's job performance, while 51 percent disapproved. While the poll's daily trend is bumpy, it's weekly averages show Obama's approval rating ranging from 40 to 45 percent from January through August, peaking slightly in the spring and early summer.

Other recent national polls also show little change, with Obama's ratings in the low 40s from earlier this year until today.

Last month, we highlighted this trend as a sign of relative good news for Obama. The fact he saw no drop in approval amid several international crises suggested his base of support is firm. But we also noted the downside of stability: Obama's detractors are equally resolute, diminishing any benefit he might receive from improving economic views or a popular air strike campaign against Islamic extremists in Iraq.

Obama's locked-in ratings also come at a poor time for Democrats, both electorally and historically. Obama gives Republicans a clear target to attack in most competitive Senate and House races, forcing Democrats into an awkward defense of their commander in chief. This challenge is on display Tuesday as Obama joins Sen. Kay Hagan (D) in all-important North Carolina, where Republican Thom Tillis has has attacked her as a loyal Obama supporter.

But Obama mattered in North Carolina even before he set foot there Tuesday. There is, after all, an increasingly close tie between the president's job approval and votes cast for Senate candidates. In 2012, a record 90 percent of voters who approved of Obama cast ballots for Democratic Senate candidates, while 82 percent who disapproved voted for the Republican, according to Emory University political scientist Alan Abramowitz's analysis. As the following chart shows, this trend has been on the rise since 1990s.

Center for Politics analyst Sean Trende spelled out how Obama's standing tethers to Democratic candidates' performance in a January Real Clear Politics article:

What I’m really interested in here, though, is that in the 31 competitive Senate races held in 2010 and 2012, the Democratic candidate has run within five points of the president’s job approval in 23 of them (75 percent). Additionally, no Democratic candidate in a competitive race has run more than 10 points ahead of the president’s job approval (or behind it).

The risk of Obama's collateral damage is largest in Democratic-held Senate seats Obama lost in 2012 -- Arkansas, Alaska, Louisiana, Montana, North Carolina, South Dakota and West Virginia -- where is job approval lags behind the already-low national average. We won't know just how much Obama's ratings will damage Democrats this fall, but his unchanging underwater approval ratings are clearly poised to take a toll.