A shift in the preference of independents from Romney to Obama has the president surging into a significant lead in the latest CBS poll. Obama also tops Rick Santorum in a survey that included registered voters - not likely voters.

CBS:

President Obama holds a significant lead over each of his potential Republican opponents in the general election, according to a poll released Tuesday by CBS News and the New York Times. That includes Mitt Romney, who was even with Mr. Obama last month.

The new survey shows the president leading Romney by six points, 48 percent to 42 percent, among registered voters. Last month, the two men were tied at 45 percent each.

Mr. Obama's lead over former Pennsylvania Sen. Rick Santorum, who has surged to a lead in national polls, is eight points: 49 percent to 41 percent.

Romney's drop in support against the president is attributable to a shift among independents. Last month, independents favored the former Massachusetts governor by eight points over Mr. Obama. In the new survey, Mr. Obama holds the edge, leading Romney among independents by nine points.

The president holds double-digit leads over the other two GOP candidates in the race, Rep. Ron Paul and former House Speaker Newt Gingrich. Mr. Obama leads Paul 50 percent to 39 percent - an 11 point margin - and he leads Gingrich 54 percent to 36 percent, a difference of 18 points.

Independent voters are abandoning Romney and now favor the president by nine points. Hard to say why - could be that Romney going negative against Gingrich turned those voters off. It could also be the slight improvement in the economy - blown up by the media as something significant - that has the indies coming back to the president.

Just remember this is a snapshot of the race as of today. What it might be next week or month is anyone's guess in this volitile campaign.