Cracks are widening between President Barack Obama and his liberal base on Capitol Hill, adding to his headaches as he tries to overcome rising unemployment and carry out a controversial new strategy for Afghanistan.

Angst in the Democratic Party’s left flank has been building all year. Liberal lawmakers chafed at Obama’s slow-walking of immigration reform and his embrace of anti-immigrant language in the health care bill. They wished he had put up more of a fight for a public insurance option. They have complained that Obama’s economic team has been too friendly to big Wall Street firms while doing too little to help small businesses and create jobs, and has tried to delay a transportation bill that would put thousands of people to work.

And now Obama appears poised to announce a massive escalation of the war in Afghanistan.

Rep. Raúl Grijalva (D-Ariz.), co-chairman of the Congressional Progressive Caucus, said liberals are growing increasingly frustrated.

“We feel that we haven’t been listened to, and yet we have to do the heavy lifting every time we pass legislation. … Compromise is about give and take but right now all we’ve been doing is giving.—

Liberal leaders have complained about being taken for granted before. Earlier this year, lawmakers squawked that they were the last major Congressional caucus to get an audience with the president; more recently liberals complained about having to compromise on issues such as health care reform.

Conflicts between Obama and liberal Members have started to affect his agenda. Before Thanksgiving, members of the Congressional Black Caucus held hostage his high-priority financial regulatory overhaul in the Financial Services Committee over differences with the Obama economic team on plans for fighting joblessness.

Liberal Rep. Peter DeFazio (D-Ore.) also tore into Obama’s economic team, calling for the resignations of adviser Larry Summers and Treasury Secretary Timothy Geithner in an MSNBC interview. “We may have to sacrifice two more jobs to get millions more for Americans,— DeFazio said.

DeFazio and Grijalva were among many liberals disappointed that more spending wasn’t included in the original stimulus package for public works projects, and they have said it’s time to pass such a package now.

Grijalva said incidents like the CBC revolt at Financial Services will continue if Obama does not start paying attention to liberals.

“You are going to see that more and more,— he said. “Back-burner issues for the administration are front-burner issues to us.—

The immediate battle is over the size and shape of a new jobs package. The administration — and Democratic leadership — has been talking about crafting a smaller, targeted package, but liberals want something bolder. The February stimulus cost $787 billion and was far-reaching.

“It has to be big and it has to be robust,— Grijalva said, contending that a few tweaks simply won’t cut it.

“I’m in Yuma County right now, where unemployment is 25 percent. A tweak is not going to help here. We need a big jobs bill. We need big, bold public projects that will put a lot of people back to work.—

Talk from the White House and Obama in recent weeks of reining in the deficit next year is raising “red flags,— Grijalva said. “The deficit is a concern, the debt is a concern, but right now I think the primary concern of the American people is the economy and the people who are unemployed.—

The Afghanistan conflict only widens the rift, because liberals see the $40 billion a year or so that the troop buildup is rumored to cost as leaving less money available to jump-start the economy here — or to revamp the health care system.

Rep. Lynn Woolsey (D-Calif.), co-chairwoman of the Progressive Caucus, said the prospect of sending 34,000 or more troops into the war-torn region “will be very unpopular— within her caucus and among House Democrats in general.

Even if Obama lays out a clear exit strategy, which could come in his Tuesday prime-time address to the nation, that is only likely to “resonate with a few people,— said Woolsey. Many would “like that exit strategy to be starting now.—

Rep. Dennis Kucinich (D-Ohio) blasted Obama for appearing ready to spend billions more in Afghanistan at a time of growing unemployment, arguing that he should focus on investing in transportation and health care in America.

“We have to ask if our leaders are really in touch with the people while there’s a separation between a finance economy and a real economy, between Wall Street and Main Street, and meanwhile we’re talking about a war, expanding it. Are you kidding me?— Kucinich said last week on MSNBC.

But not all liberals are willing to take the gloves off.

CBC Chairwoman Barbara Lee (D-Calif.) called the prospect of troop increases “totally unacceptable— but adamantly refused to say she was upset by the president’s lack of action on liberal priorities.

“I am not frustrated. The answer is no, no, no,— Lee said. On Afghanistan, “I have to commend the president for the way he’s doing this, for being very deliberative and taking his time.—

Likewise, Lee brushed off the fact that Obama opposes moving a $500 billion transportation reauthorization bill this year — a package with strong Democratic support because of its job-creating potential. “This is still in the early stages,— Lee said. “We’re the Congress and we’re working hard to make sure we get the best possible jobs bill.—

Woolsey acknowledged that Obama is not delivering to liberals on many of their key issues, but added, “I didn’t expect him to be a progressive, so personally, I’m not surprised.—

“First of all, I was a Hillary [Rodham Clinton] supporter [during the Democratic presidential primary] because I knew where she stood,— Woolsey said. “I wasn’t against Obama. … But I never did think of him as a progressive politician.—

Woolsey said she expected Congress to pass the transportation package this year and send it to the president, regardless of his desire to punt on it until 2011.

“Jobs are still not improving, so the average Joe Lunch Bucket is not getting any benefit out of this ‘improved economy,’— Woolsey said.

Democratic leaders seem keenly aware of the growing rumblings from the left of their Caucus.

“It’s something that [Obama’s] advisers need to understand,— one leadership aide said. “All of the attention given to the moderates in the Caucus has created this frustration or discontent in the rest of the Caucus, that their views are not as valued. … His advisers need to get a better ear for that dynamic.—

But the aide said that most Members are airing their misgivings privately and described the tensions as a natural outgrowth of the Democratic Party’s diversity.

And Obama does get some slack from Members because of the mess he inherited, the aide said. “This isn’t a time of peace and prosperity, and he’s had to tackle a lot of major challenges from day one. … None of these challenges are easy and none of them are going to get you high approval ratings overnight.—

Jennifer Bendery contributed to this report.