With the presidential election just weeks away, each day brings an onslaught of new polls. Experts admit the results aren't always uniform because no two samples are ever alike, and there are multiple methodologies used to interpret the results.
In recent days, some supporters of Mitt Romney have objected to polls they argue include too many Democrats in the mix. Pollsters across the board say it's not unusual to have one party more highly represented than another, and in years past it was Republicans who seemed to have the advantage.
Scott Rasmussen, founder and president of Rasmussen Reports, says reputable pollsters start by first making sure they have a sample that reflects the U.S. population demographically: gender, race and household income. It's only after establishing those criteria that most pollsters will ask respondents, not which party their registered with, but with which party they feel most aligned. In recent weeks, a number of pollsters say they've seen a shift by unaffiliated voters -- into the Democrats' column.
Longtime Democratic strategist Joe Trippi says Republicans should take note of the less-than-ideal numbers for their camp. "The good news is it's 40 days or so out," Trippi says, adding, "You've got time to do something about it." He warns that denying the shift has happened won't help the Romney camp figure out how to combat it.
Rasmussen believes unaffiliated voters are still very much up for grabs, saying they initially gave President Obama high marks and then cooled. He says that in 2011 "they were strongly against him," and while "most unaffiliated voters do not approve of the president, their hostility is not what it was a year ago."
There is agreement among most pollsters that the 2012 electorate will be markedly different than 2008, as young and minority voters are expected to be less likely to show up at the polls this time around.
Experts say polls do have specific impact -- on both donations and volunteers' willingness to work for the candidate they're supporting. Consultant and pollster Pat Caddell says it also shapes the media's narrative. "Is it a close race or as the mainstream media is constantly trying to, in my opinion, orchestrate -- is Obama is inevitable ... he's got this thing wrapped up."