Despite millions of dollars in ads by backers of "dirty energy," American voters continue to believe President Obama will do a better job on energy than Republican candidate Mitt Romney, according to a newly released poll commissioned by environmental groups.

Voters in battleground states picked Obama in spite of an unprecedented number of ads bashing the president over the Keystone XL pipeline, the failed solar manufacturer Solyndra and regulation of coal, the groups said.

"This election was supposed to be about wealthy Big Oil-backed special interests spending unprecedented resources to wipe pro-environment candidates off the map," said Gene Karpinski, president of the League of Conservation Voters. "But voters chose a different course."

LCV was joined at the National Press Club today by the political arms of the Natural Resources Defense Council, Defenders of Wildlife and National Wildlife Federation in addition to the Sierra Club and Environment America.

It was a victory lap, of sorts, for groups that spent big in key Senate races in states including Montana, Maine and New Mexico, backing candidates who they argued would support the environment. The goal was to ensure the Senate would remain a "firewall" against anti-environment legislation from the House, and it worked, Karpinski said.

"We're all smiling today," he said. "Big Oil lost big time."

The poll by Greenberg Quinlan Rosner Research was conducted nationally this week and surveyed more than 1,000 voters in 11 battleground states.

It found that energy was cited by 14 percent of voters as the best reason to vote against Obama, falling in last place among Romney voters behind other Republican message points including debt and spending, Obama's health care reforms, family values, and government regulation.

The poll also found that by a 54 percent to 39 percent margin, voters favored continued government tax credits for clean energy companies over arguments that the government shouldn't be picking winners and losers.

A majority of those polled agreed U.S. EPA "should be allowed to make common sense rules" to protect Americans' health that are based on science and immune to political interference.

According to the environmental groups, outside "polluter-backed" groups and those siding with "dirty energy" spent more than $270 million on television ads in the last two months of the 2012 election cycle. More than $30 million of the funds supported energy-related ads.

Karpinski said green groups spent more on this election than in the past three election cycles combined.