DENVER — The latest survey of Colorado voters by Public Policy Polling shows President Barack Obama as the favorite to win this critical swing state come November.

According to the poll, Obama leads Republican Mitt Romney by a margin of 49-42 percent.

That’s a much larger margin than the Purple Strategies poll released earlier this month that showed the race within the margin of error as Obama held a slim 48-46 lead in Colorado.

In hindsight, PPP’s last survey, which showed Obama up on Romney 53-40 in the state, looks to be a serious outlier; and conservatives often charge that the firm is notorious for over-sampling left-leaning voters.

In its polling memo Tuesday, PPP acknowledges that Romney has improved since the GOP nomination process came to an end.

“Romney’s seen a major improvement in his image in Colorado, as he has nationally, since GOP voters unified around him,” the pollsters concluded.

“His numbers still aren’t terribly impressive with 40% of voters rating him favorably to 52% with a negative opinion. But that’s up a net 17 points from April when he was at 31/60.”

According to pollsters, Obama continues to do much better than Romney among Latinos — Obama leads Romney 60-33 — and women — Obama tops Romney 54-40.

Romney has closed the gap with independent voters of late, but still trails Obama there too by a margin of 48-38.

Romney leads Obama by a 53-39 margin with voters over the age of 65, but trails Obama by a whopping 58-29 margin with voters under 30.