Gallup has released an interesting new poll on President Obama’s tax promises:

A new Gallup Poll finds that 68% of Americans believe their federal income taxes will be higher by the time Barack Obama’s first term as president ends. This includes 35% who say their taxes will be “a lot higher.”

Obama campaigned on the promise that he would raise income taxes on only the wealthiest Americans. While Americans were not necessarily convinced of that at the time — in Gallup’s final 2008 pre-election poll, 49% thought their income taxes would be higher if Obama were elected — many more expect a tax hike now than did so during the campaign.

The rise in expectations that taxes will go up probably is a reflection on Obama’s ambitious domestic agenda, which began with a $787 billion economic stimulus plan and is now focused on a roughly $1 trillion healthcare reform bill. Still, the Obama administration has made no definite plans to increase income taxes on any but the wealthiest Americans.

Despite this, even a majority of Americans in the lowest income group — whose annual household incomes are less than $30,000 — believe their taxes will go up. Much larger majorities of middle- and upper-income Americans expect their taxes to be raised. Part of that relationship could be explained by the fact that upper-income Americans tend to be more Republican in their party orientation.

But even Obama’s political base has doubts about his being able to hold the line on income taxes — 48% of Democrats expect their taxes to rise during his first term. More than 7 in 10 independents and 9 in 10 Republicans agree.