LAKEWOOD, Colo. -- Republican vice presidential candidate Paul Ryan campaigned in Colorado and Nevada on Tuesday, blaming President Obama for the lost jobs and plummeting home prices that have plagued the two critical swing states.

"Here is our promise to you," Mitt Romney's running mate told one cheering crowd. "We are not going to duck the tough issues. We are going to lead."

It was only Ryan's fourth day on the presidential campaign trail and just his second solo outing. But the seven-term Wisconsin congressman is already establishing himself as the party's chief attack dog against Obama.

And Ryan is tracking his prey, following Obama, who campaigned in Colorado last week and Nevada in July, into areas that were hit the hardest by the home foreclosure crisis but expected to play pivotal roles in the November election.

"It sounds like part of their strategy is to begin to go places Obama has gone and talk about the ways that Obama's policies have not worked," University of Colorado at Boulder political science professor Kenneth Bickers told The Washington Examiner.

Polls give Romney an edge in Colorado and show Obama slightly ahead in Nevada. But the Silver State's economic slump and depressed housing market could create an opening for the GOP, said Jon Ralston, a top political analyst in Las Vegas.

"Romney has a shot at the state," Ralston said. "I just think he's an underdog." Ryan's addition to the ticket, he said, "may make no difference at all."

Appearing in Colorado on Tuesday, Ryan emphasized Romney's commitment to an "all of the above" energy-production policy -- one that encourages continued use of fossil fuels as well as new fuel sources -- in a state where three renewable energy companies closed or scaled back this summer despite hundreds of millions in federal loans from the Obama administration.

Oil drilling in Colorado has been hurt by rising prices and by administration policies that made it more difficult to obtain permits to drill on public land.

"President Obama has done all that he can to make it harder to use our own energy," Ryan said, pledging that a Romney administration would "streamline the regulations and open up these resources so we can create jobs."

As Ryan addressed the crowd in Lakewood, Romney campaigned in Ohio, where he bashed Obama for waging a policy "war on coal" that has made it harder and more expensive for coal plants to operate.

At a coal mine in Beallsville, with miners standing behind him, Romney pledged that he would free the country from its dependence on foreign energy by 2021.

In Colorado, the crowd cheered the Republican plan to expand domestic oil and gas exploration.

"We have lots of resources in this state, and they need to be found and used," Glen Brougham, 61, of Evergreen, told The Examiner. "We should not be limited by our government."

Bickers said Ryan may help the Romney campaign in Colorado because voters there are younger than in states like Florida, where Ryan's plan to overhaul Medicare may turn off the heavy base of senior voters.

Sean Golden, 29, said he likes Ryan, but that his plans for energy production are less important than his economic plan and proposals to reduce the nation's massive budget deficit.

"I want someone who will cut programs," Golden said.