Public impressions of the two political parties are similarly gloomy. Favorable ratings for the Democratic Party (39 percent) are at a 30-year low, and for the first time a majority (51 percent) gives the Democrats an unfavorable rating. The Republicans are even lower, with a 33 percent favorable rating. That is little changed since last year’s government shutdown, although the party’s unfavorable rating has improved.

Most worrisome for Democrats is that their candidates will be weighed down by unhappiness with the president. Obama’s overall approval rating stands at 40 percent, the lowest recorded in a Post-ABC News poll during his six years in office, though only a point lower than last month. Among independents, his rating is 33 percent…

But public support for his handling of the threats posed by Islamic State extremists has tumbled dramatically in just the past few weeks, falling from 50 percent approval at the end of September to just 35 percent today. Three weeks ago, his rating on dealing with the Islamic State insurgents was a net positive by six points. Today it is net negative by 16 points.

On other measures the president is at or near low points, whether international affairs, terrorism or implementation of the Affordable Care Act.