US conservatives are stepping up efforts to defeat Barack Obama in Virginia, a state the first US black president carried four years ago.

Six months before the election, Virginia is poised to become one of the great battlegrounds of American politics.

Since December, Pete Snyder, chairman of the Republican group "Virginia Victory 2012," crisscrossed the state to mobilize his best forces.

"The mission at 'Virginia Victory' is to make sure that the 13 electoral votes that Virginia has go for the Republican nominee, and that we win back the US Senate seat," Snyder told AFP.

Presumptive Republican nominee Mitt Romney heads to America's largest Christian university Saturday to court young religious conservatives and push family values in the wake of Obama's gay marriage endorsement.

Romney will also urge graduates not to "lose heart" in the face of diminished job prospects when he gives the commencement address at Liberty University in this small city in central Virginia, according to excerpts of his speech released by the campaign.

Recent polls show Obama and Romney are running neck-and-neck in several key states, including Virginia.

According to a recent survey conducted by the website RealClearPolitics, Obama has a slight lead over Romney in Virginia -- 47.5 percent versus 44.3 percent.

Romney's visit to Liberty University is also seen as a rallying cry to evangelical Christian voters, a crucial constituency in Virginia.

Paul Sapperstein, vice president of a Republican student association at Liberty University, said that "Mitt Romney made a very wise choice, even though there are differences in every way."

"There's no question the Evangelicals are very important group for the Republican candidate to win," Sapperstein added. "I believe they will support him. It's a vote for Romney, but it's also a vote against the current administration."

A non-profit group, Americans For Prosperity, organized in a suburb of Richmond Friday a small discussion among conservatives about President Obama's energy policy.

Gas prices remain high in the United States, even though they have gone down recently.

"The political ideology of the White House is bankrupting us," said Audrey Jackson, a state coordinator for the group, denouncing restrictions on oil drilling, especially off the coast of Virginia.

"We're sending a message to the president: stop tanking America," she added.

The association plans to get his message across in seven key battleground states for the November presidential election.

In the audience, Phil Scott, a 62-year-old real estate broker, said that, in his view, "anybody is better than what we have now."

He said he was already involved in the campaign and while Romney was not his first choice, he was determined to do everything for the Republican nominee by working as a volunteer and going door to door.

James Knesel, 70, a retiree from the Navy, said he was "not sure Mitt Romney has the stamina to take on the economy."

"But I'm going to trust him in November," he pointed out. "Because I absolutely want to get rid of Obama."