When the going gets rough, blame the other guys. That appeared to be President Obama’s game plan Monday as he attacked congressional Republicans at the start of a three-day bus tour across North Carolina and Virginia. Both are states he won in 2008 that could be hard to hold onto in next year’s presidential race.

Mr. Obama started in Ashville, N.C., a liberal haven in the conservative western part of the state, and wasted no time in lashing out at Senate Republicans for blocking consideration of his $447 billion jobs bill last week.

“They said no to putting teachers and construction workers back on the job,” Obama said to a crowd at Ashville Regional Airport. “They said no to rebuilding our roads and our bridges and our airports. They said no to cutting taxes for middle-class families and small businesses when all they’ve been doing is cutting taxes for the wealthiest Americans.”

Obama then described the Republican jobs plan in the most caustic of terms: “You got their plan, which is, Let’s have dirtier air, dirtier water, [and] less people with health insurance.”

The president confirmed his plan to break up the jobs bill into smaller pieces. “Maybe they just couldn’t understand the whole all at once,” he said, adding that he would start with a bill to fund the jobs of hundreds of thousands of teachers, police officers, and firefighters.

Senate majority leader Harry Reid (D) of Nevada was expected on Monday afternoon to announce the introduction of a $35 billion Teachers and First Responders Back to Work Act, though the Senate may not take it up right away.

The White House insists Obama’s bus tour through North Carolina and Virginia is all about policy and not politics, but the president’s uphill effort at reelection next year is hard not to see. North Carolina barely squeaked into the Obama column in 2008, choosing him over Republican John McCain by only about 14,000 out of 4.3 million cast (49.7 percent to 49.4 percent).

Obama can still win reelection without North Carolina’s 15 electoral votes, though political handicappers say the odds are against him. But the Democrats aren’t giving up. They’re holding their national convention in Charlotte, N.C., next September, and the state’s Democratic governor, Democratic junior senator, and handful of Democratic House members could help support the president.

But with unemployment higher than the national average at 10.4 percent, and Obama’s job approval rating at 42 percent, according to a poll by the North Carolina-based Elon University, he has work to do.

Obama’s bus tour demonstrates the demographic diversity of North Carolina, and different constituencies he is trying to attract:

In Ashville, he is pitching to his liberal base – people he needs not only to vote for him but also to volunteer and donate money.

In small-town, predominantly white Millers Creek and Jamestown, he is appealing to the political independents, who were a key swing group in 2008 and will remain central in 2012.

In Greensboro, where he will be on Tuesday, 40 percent of the population is African-American. Obama will not win reelection without high black turnout.

On Wednesday, the president heads north into Virginia, whose different regions mirror those of North Carolina. In 2008, the commonwealth voted for a Democrat for the first time since 1964, but Obama won convincingly – 53 percent to 46 percent – and has a better shot at winning there again than he does in North Carolina. Unemployment is 6.3 percent, well below the national average of 9.1 percent. His job approval is at 45 percent, according to the Quinnipiac University poll.

Obama’s sweeping victory in 2008 means there are several states he could lose in 2012 and still win the election. For example, he could lose the five states he carried with the closest margins of victory – North Carolina, Indiana, Florida, Ohio, and Virginia – and still come up with the 272 electoral votes he needs to win, according to Larry Sabato and his team at the University of Virginia Center for Politics.

So while North Carolina is not do or die in 2012, if he can win there and in Virginia, it lowers the pressure in other swing states that could be hard to win, such as Ohio.