To no one's surprise, the next Washington political showdown reared its partisan head on Tuesday.

Some House Democrats rejected a GOP proposal intended to fund the government through September while maintaining the forced spending cuts that took effect last week but softening their impact.

Failure by Congress to approve a government funding measure, known as a continuing resolution, could cause a partial shutdown when current funding authorization expires on March 27.

While The White House and congressional leaders signaled they don't want another fiscal crisis over keeping the government funded like the ones that dominated President Barack Obama's first term, an administration policy statement indicated the battle over the forced spending cuts will continue.

Meanwhile, a new poll indicated the impasse over spending cuts could be hurting Obama and Democrats, but not necessarily helping Republicans.

The mandatory, across-the-board cuts to defense and other discretionary government spending -- but not entitlement programs such as Social Security and Medicare -- occurred after Obama and Congress were unable to work out a compromise to replace or avert them.

They amount to roughly 9% for a broad range of non-defense programs and 13% for the Pentagon over the remaining seven months of fiscal year 2013.

While both sides oppose the government-wide nature of the cuts, with no leeway for shifting funds to protect specific programs, conservatives argue the total amount is a manageable slice in spending while Democrats say it will cause unnecessary harm.

The harshest impacts won't be evident until April at the earliest, but economists and leaders of both parties warn the $85 billion in cuts through fiscal year 2013 will slow the economy and cause pain for many Americans.

On Tuesday, the Federal Aviation Administration notified control tower operators that 173 of the air traffic towers at small- and medium-sized airports would close on April 7 because of the forced spending cuts, known in Washington jargon as sequestration.

The towers operated by contractors instead of FAA employees account for less than 6% of commercial airline operations, and closing them would not necessarily result in airport closures.

A more immediate impact came on Tuesday when the White House announced it was canceling all tours effective this Saturday and until further notice to cut costs.

"Unfortunately, we will not be able to reschedule affected tours," the White House said.

Republicans complain the Obama administration has tried to manipulate the spending cuts to generate public outrage instead of making a good faith effort to implement them in the most effective and least harmful manner possible.

White House spokesman Jay Carney responded to such criticism Tuesday, saying he found it "remarkable that those who weeks ago and certainly months ago were decrying sequester as the worst possible thing that could happen now embrace it as a victory."

Last week, the Army sent the first furlough notices for government employees due to the mandatory cuts.

The notices warned unions that workers at the Aberdeen Proving Ground in Gunpowder, Maryland, as well as the Corps of Engineers in Walla Walla, Washington, will be forced to stay home without pay one day each week from April 22 through Sept. 21.

That translates to a 20% pay cut for five months, the kind of economic hit that Obama and others have warned will harm the nation's still sluggish recovery from recession.

Other impacts outlined by government officials include reduced staffing at airport customs and security checkpoints, resulting in longer lines; a later opening for gates at Yellowstone National Park because of delayed snow plowing to save money, and job cuts at some schools.

Susan Smit, a superintendent in Wagner, South Dakota, told an education conference on Monday that her district reduced health benefits and did not re-hire some staff members in anticipation of the reduced federal funding.

In addition, military leaders say force readiness will decline if the full impact of sequester -- totaling about $1 trillion over 10 years -- were to take effect.

On Tuesday, the commander of U.S. special operations forces told a congressional committee that the spending cuts and the pending need to fund the government for the rest of the fiscal year would mean less money for the military.

Adm. William McRaven, who heads the U.S. Special Operations Command, said a new continuing resolution might revert to 2012 spending levels, which would be $1.5 billion less than what was planned for 2013.

On top of that would be an additional $900 million in cuts due to sequestration, resulting in "about a 23% cut from Southern Command's available resources," McRaven said.

"I think I can manage that with the resources we have," he told the Senate Armed Services Committee. "But we are beginning to create a readiness problem if we don't resolve the (continuing resolution) and/or have an opportunity to manage the sequestration money because I am already cutting 60% of my flying hours back" in the continental United States, as well as reducing future deployments.