PHOENIX - Most Arizonans no longer think Barack Obama is doing a decent job as president.

A new Behavior Research Poll released Sunday shows that nearly four out of every 10 Arizonans now rate Obama's performance as poor or very poor. That's up 5 points from the same survey taken in January.

What's different is that the number of those who think he's doing an excellent or good job has plummeted.

Three months after taking office, fully 51 percent of Arizonans gave Obama positive ratings, even though the state went for hometown favorite John McCain in the 2008 election.

A year into office, that had slid to 40 percent. But by the time pollster Earl de Berge conducted this latest survey, between June 30 and July 11, only 28 percent of Arizonans were willing to say they like the job he's doing.

According to de Berge, much of that slide tracks with a separate poll he does asking Arizonans about their views on the economy and current job market conditions.

"As might be expected, those who think the job market is static or worsening have the least favorable view of his performance," de Berge said.

But the survey also was taken about the time it became clear that the Department of Justice, asked to look at Arizona's new immigration law, intended to file suit. In fact, Secretary of State Hillary Clinton, in an interview with a television station in Ecuador, spilled the beans early in June.

That all became official when the Obama administration went to federal court on July 6 - right in the middle of the polling - asking a judge to block the statute from taking effect as scheduled July 26.

The law, which spells out when police have to ask those they have stopped about their immigration status, is popular in Arizona, with every single survey showing it's backed by more than half of residents.

Obama maintains his popularity with Democrats, 52 percent of whom still have a positive assessment of his work. Still, that's down from 85 percent in April 2009.

His positive rating among independents, which was 54 percent in that first post-election survey, now has dropped to 22 percent. And 8 percent of Republicans now score his performance as excellent or good.

The survey of 800 adult heads of households has a margin of error of 3.5 percent.