A new Wall Street Journal/NBC poll showing Americans with shattered confidence in President Obama's ability to lead may be bad news for him, but it's worse news for liberalism.

In his 2008 campaign, Obama sought to make the election about more than merely voting for another Democrat. He spoke in terms of transforming the country, obliterating the cynicism that Americans had about the federal government, and showing them that it could be effective.

“I think Ronald Reagan changed the trajectory of America in a way that, you know, Richard Nixon did not and in a way that Bill Clinton did not,” candidate Obama said.

In some senses, Obama did change the trajectory of America. For instance, he passed the most significant expansion of entitlements since Lyndon Johnson's Great Society in the form of his health care law.

But going into the sixth year of his presidency, Obama still hasn’t sold Americans on his view of the role of government, which could have significant ramifications for the liberal agenda in the future.

True, there are some issues, such as global warming, in which the poll showed the public closer to the liberal view. But not on the overarching question that has been at the center of American politics since the New Deal era.

According to the poll, just 46 percent of Americans agreed with the statement that, “Government should do more to solve problems and help meet the needs of people” compared with 50 percent who agreed with the view that, “Government is doing too many things better left to businesses and individuals.” In February 2009, right after he was sworn into office, the same poll found 51 percent thought government should do more and just 40 percent who thought it was doing too much.

A lot has been made about the poll's finding that the public now views the Obama administration as less competent than that of President George W. Bush in the wake of Hurricane Katrina, as well as another finding that 54 percent of respondents no longer feel that “he is able to lead the country and get the job done.”

But what I found more worrisome for liberals was another question, which asked about the problems with the Department of Veterans Affairs. It found that just 14 percent blamed the problems on “poor management by the Obama administration” compared with 61 percent who blamed “longstanding government bureaucracy.”

On the surface, it would seem to be good news for the left that the public doesn't pin the blame on Obama. But as I detailed in a column last month, liberals once touted Veterans Affairs hospitals as evidence that government-run health care could work and even outperform the private sector.

To the extent that Americans see problems as connected to Obama’s incompetence, it still provides an opening for another Democrat to implement the liberal agenda. But if Obama-era failures make Americans more skeptical about federal bureaucracy in general, it makes things that much more difficult.

Obama, in his first Inaugural Address, said: “Now, there are some who question the scale of our ambitions, who suggest that our system cannot tolerate too many big plans. ... What the cynics fail to understand is that the ground has shifted beneath them, that the stale political arguments that have consumed us for so long no longer apply.”

He continued, “The question we ask today is not whether our government is too big or too small, but whether it works.” Obama set out to convince Americans that government could work, and as of this point in his presidency, he has failed.

Obama was correct that Bill Clinton didn't change the trajectory of America - but he was constrained because Reagan's small government message still resonated with the public. That's why Clinton had to famously declare an end to the "era of big government."

Just as Bill Clinton was constrained by Reagan’s successes, even if Hillary Clinton gets elected, she may find herself constrained by Obama’s failures and unable to advance a sweeping liberal agenda.