Public Policy Polling for Daily Kos and SEIU (6/9-12, MoE: ±3.1, registered voters, Obama trendlines 6/2-5, all others 5/19-22):
Favorables:
Barack Obama: 51-45 (49-46)
Democratic Party: 46-47 (44-48)
Republican Party: 32-54 (32-55)
Job Approval:
Barack Obama: 49-49 (44-48)
Harry Reid: 24-43 (25-43)
Mitch McConnell: 18-35 (20-36)
Though the week-to-week fluctuations in our polling (or any polling) seldom mean much, it's always interesting to see why the numbers have moved. In this case, Barack Obama has seen a slight uptick in both his favorability rating and his job approvals. Sometimes these shifts happen because of major newsworthy events (the killing of Osama bin Laden is a prime example), sometimes it's a slow evolution of attitudes, and sometimes it's just because our sample composition changes.
Here, it looks like the last option is the cause. A week ago, 37% of our respondents identified as Democrats, while 34% said they were Republicans. This week, the GOP proportion stayed the same, but Dems shot up to 42% of the sample. It's a good reminder that unlike other demographic measures such as race, age, or gender, party ID tends to be very fluid. Some people (particularly those apt to otherwise call themselves independents) are simply more apt to change their minds from time to time and actually settle on a party.
These shifts sometimes are just noise, but sometimes they are harbingers of real changes in mood. For instance, after the bin Laden news came out, more people (temporarily) started identifying themselves as Democrats. While this week's move is likely ephemeral rather than long-term, it's an important reason why we do not weight our polls by party ID. Pollsters who do that risk missing out on genuine trends in the electorate.