NEW YORK - President Barack Obama holds a significant lead over each of his potential Republican opponents, including Romney,  in the November general election, according to a New York Times/CBS News poll released Tuesday.

Consecutive months of job growth, the bullish stock market and improving consumer demand appear to be benefiting the president who stated outright three years ago that his chances for a second term would depend on his ability to persuade the country that its economy was on the mend by this very month, the poll says.

It shows that the percentage of people who said they believed the economic outlook was improving is now greater, by double digits, than the percentage of those who said they believed it was getting worse, a reversal from a low point in September, when pessimists outnumbered optimists by by more than three to one. 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.

Obama’s lead over former Pennsylvania Senator 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 favoured the former Massachusetts governor by eight points over Obama. In the new survey, Obama holds the edge, leading Romney among independents by nine points.

The president holds double-digit leads over the other two Republican candidates in the race, Congressman Ron Paul and former House Speaker Newt Gingrich. 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.

The findings come as the Republican candidates seek to cast themselves as the potential nominee with the best chance of beating Obama in November. Santorum is out with a new ad in Michigan, which holds its primary on February 28, which opens: “Who has the best chance to beat Obama? Rick Santorum.” Santorum holds a narrow lead over Romney among Republican primary voters nationwide, according to the new survey. Santorum had the support of 30 percent of Republican primary voters, followed by Romney at 27 percent, Paul at 12 percent and Gingrich at 10 percent. (The difference between Santorum and Romney is statistically insignificant, as it is within the poll’s three point margin of error.) Santorum, who has gained momentum from a three-state sweep, last Tuesday, was at just 16 percent nationally last month.

Romney is widely seen as the candidate with the best chance to beat Obama: 55 percent of Republican primary voters say Romney is the most electable candidate. No other candidate is seen as having the best chance to win by more than 15 percent of GOP primary voters. But Romney is not seen as reflecting Republican primary voters’ values. Just 23 percent say Romney is the candidate who best represents their values, while 39 percent choose Santorum.

Roughly one in three Republican primary voters say Romney, who has been attacked over his moderate record as Massachusetts governor, holds views that are not conservative enough. By contrast, only seven percent say that Santorum’s views are insufficiently conservative. Santorum leads Romney by at least twelve points among the most conservative members of the Republicans: self-described conservatives, Tea Partiers and white evangelicals.

And while at least half of Republican primary voters say Santorum, Gingrich and Paul would offer policies that would be “very different” than Obama, just 36 percent say Romney’s policies would be “very different” than those of the president.

Santorum is also seen as the candidate most likely to help the middle class: Thirty-two percent of Republican primary voters say Santorum would be most likely to help middle class Americans, while 19 percent cite Romney, 18 percent cite Gingrich and 18 percent cite Paul. Among registered voters overall, 53 percent say Romney favours the rich over other Americans; only 31 percent say the same of Santorum.

Republican primary voters remain dissatisfied with their candidates: 62 percent say they want more choices while 34 percent say they are happy with the field. Sixty percent of GOP primary voters who have picked a candidate say they could still change their mind, while 39 percent say they have settled on a candidate.

The survey, conducted from February 8-13, also found Obama’s approval rating reaching 50 percent amid rising optimism over the economy.