Three years ago, Democrats in Virginia couldn’t get enough of Barack Obama — a popular, transformational figure running for his first term as president.

But as Obama arrives in Virginia Tuesday for a two-day swing to promote parts of his jobs plan, some Democrats are distancing themselves from him — even in supposedly blue Northern Virginia.

Less than a month before critical legislative elections, several Democratic legislators say they have reservations about the president and will not commit to supporting him next year. At least one longtime state senator has announced he will not vote for Obama in 2012.

“He’s frustrating me, just like he’s frustrating others out there,’’ said Sen. Linda T. “Toddy” Puller, a Democrat who faces Republican Jeff Frederick in a tough reelection campaign in Fairfax and Prince William counties.

House Minority Leader Ward L. Armstrong (D), who is fighting for reelection after Republicans eliminated his district during redistricting, released a TV ad in response to an attempt by his Republican opponent, Del. Charles D. Poindexter, to tie him to Obama in the Southside district.

In the ad, Armstrong dismisses the notion. “That’s a stretch, Charles. I’m pro-life, pro-gun, and I always put Virginia first.”

Nationally, Obama’s job-approval ratings have sunk, as a stalled economy has bled millions of jobs and congressional partisan bickering has led to a downgrade of the federal government’s credit rating.

Even before the president’s trip was announced, Republicans in Virginia had been tightening the screws, aggressively challenging Democrats’ hold on the state Senate in part by tying them to the president. Recent polls and interviews with voters show that Republicans may have had some success.

“The last thing they want to do is be tied to the hip of an unpopular president,’’ Lt. Gov. Bill Bolling (R) said. “If he wanted to help these Democrats, he would stay far away from Virginia. They’re trying to save their skin.”

Obama began a three-day bus tour Monday in North Carolina and will continue Tuesday and Wednesday in Virginia — two critical swing states he carried in 2008 that remain just as important in 2012.

In 2008, Obama became the first Democratic president to carry Virginia in more than four decades, leading some Democrats to declare the state blue. But in the years since, Democrats — lagging in money and candidates ahead of next month’s races — have lost ground in what some still consider a conservative Southern state. The GOP controls most of Richmond and holds a commanding majority of Virginia’s congressional delegation.

Virginia is expected to remain a swing state. Last month, the Gallup poll tracking Obama’s approval ratings showed that the 2012 presidential election will come down to 10 states, including Virginia. Even Rep. Gerald E. Connolly (D-Va.), who barely won reelection last year, said in August that Obama would not win Virginia if the election were held now.

The White House had considered stops in Danville, Newport News, Charlottesville and Fredericksburg. But prominent Democrats in Virginia — where Obama’s approval rating hovers around 50 percent — encouraged the White House to alter the schedule so he would no longer visit districts where members of his party were involved in tight elections.

Instead, Obama will speak at a high school in Emporia on Tuesday, and Langley Air Force Base in Hampton and a fire station in Chesterfield County outside Richmond on Wednesday. He will be joined by first lady Michelle Obama in Hampton.

Democratic legislators say they constantly hear from residents who are frustrated that Washington fails to get things done. Complaints were most pronounced when Obama and Congress were locked in a battle over raising the nation’s debt ceiling and the federal government lost its top credit rating.

State Sen. George L. Barker (D-Fairfax), who is in danger of losing his seat, said Republicans who supported him in 2007 have told him they will not vote for him because of Obama.

“Clearly, I’m going to lose some Republicans who would have otherwise voted for me,’’ he said.

In 2007, President George W. Bush’s unpopularity was blamed in part on the GOP losing the state Senate in Virginia’s off-year elections.

Next year, when Obama is at the top of the ticket, many Democrats will have to embrace him, knowing their fates are intertwined. But that’s not necessarily the case 13 months in advance.

Sen. Phillip P. Puckett (D-Russell), who faces a tough reelection battle in Southwest against Republican Adam Light, became the first Democratic legislator in the state to say he would not be supporting Obama in 2012.

Puckett made his comments last month after Republicans put up billboards in his rural district showing him campaigning for Obama in 2008.

“It’s very clear to me that the administration does not support the coal industry in a way that’s beneficial to our area,’’ he said in a taped TV interview. “So, I don’t plan to support President Obama for reelection.’’

In an interview with The Washington Post, Armstrong declined to say whether he would support Obama next year.

“I am who I am and I am for what I stand for,’’ he said. “I am interested in being the best delegate that I can be in Richmond. I’m about a race that’s going on in 2011; 2012 will be 2012.”

Sen. William Roscoe Reynolds (D-Franklin), Sen. R. Edward Houck (D- Spotsylvania), Barker and Puller also declined to say if they would vote for Obama next year.

“I’m going to let the president run his campaign and I’m going to run mine,’' said Houck, who faces Republican Bryce Reeves in the Frederickburg area.

Republican Bill Stanley, who lost his Senate seat to redistricting and moved to challenge Reynolds, has tried to push Reynolds on the subject.

“In three years we haven’t seen anything to turn the economy around,’’ he said. “The real question is does Roscoe Reynolds support the policies of Barack Obama?”

Reynolds said it’s too early to talk about Obama’s reelection campaign, and that he doesn’t know what impact Republicans’ efforts will have on his race.

“Who knows?” he said.