Democrats and Republicans will squabble over important issues in the 110th Congress — healthcare, the Iraq war, the proper role of government. But lately, tensions are boiling over one, far smaller, matter. One about the size of an adjective, or maybe just a syllable.

Mention it to lawmakers, and their responses run the gamut.

“Wasn’t that nasty?” Sen. Chris Dodd (D-Conn.) replied with an amused grin as he made his way to the Senate elevators.

“That’s a problem,” Sen. Dick Durbin (D-Ill.) said, shaking his head disapprovingly.

“I have no thoughts about it,” Sen. Barack Obama (D-Ill.) concluded, after pausing a moment to think about it.

“I guess I’m surprised it’s a big issue,” a puzzled Sen. John Thune (R-S.D.) responded.

The president lopped off the “-ic” in “Democratic” when he congratulated the “Democrat majority” in last week’s State of the Union address.

It sounded like a small thing, a slip of the tongue. Bush denied it was intentional in a radio interview yesterday. But it was not lost on congressional Democrats, many of whom regarded it as a deliberate slight intended to imply they are no more “democratic” than their colleagues across the aisle.

The president has a habit of muffing the Democratic Party’s chosen name — one that he hasn’t kicked since he called for bipartisan unity after his party’s defeat in the midterm elections.

A quick search on the White House website yields at least 10 instances in which Bush used “Democrat” as an adjective since Nov. 7.

For example, on the morning after Election Day, he declared, “It is clear the Democrat Party had a good night last night, and I congratulate them on their victories. This morning I spoke with Republican and Democrat leadership in the House and Senate.”

But Bush isn’t the only Republican stumbling over the D-word since Congress convened this year. House Majority Leader John Boehner (R-Ohio) uttered “Democrat Party” in his Jan. 4 speech before passing the gavel to new Speaker Nancy Pelosi (D-Calif.).

Reps. Patrick McHenry (R-N.C.) and Pete Sessions (R-Texas) have referred respectively to the “Democrat majority” and “Democrat leadership” on the House floor.

And, in his opening remarks to the House Education and Labor Committee, ranking member Buck McKeon (R-Calif.) spoke of his shared desire with Chairman George Miller (D-Calif.) to craft sensible reforms. “But this goal is not a Republican or Democrat goal,” he said.

The examples go on. But the Democratic leadership may have bigger fish to fry than worrying about what Republicans call them. Spokesmen for Pelosi and Rep. Rahm Emanuel (Ill.), the chairman of the Democratic Conference, declined to comment on the matter.

Yet Miller, a close ally of Pelosi’s, regards it as a “calculated slur” against his party. “It’s a bit like grade school. There’s an amount of childishness in it,” he said.

“We thought that they might consider this a losing strategy after the election,” he continued. “He’s the leader of the entire nation, he’s not some schoolyard bully.”

Daniel Weiss, Miller’s chief of staff, is keeping a running tally of the instances when Republicans mangle his party’s name.

“I follow it because I care about the language,” he explained. “When the language gets misused long enough, it catches on.”

Weiss has noted several instances of the press using the word “Democrat” inappropriately. He was irked to see a constituent do so, probably deliberately, in a recent e-mail to his boss.

“Indeed, the whole question of the Democrat Party policy about the War on Terror is, what is it?” the person wrote.

Republicans have a long history of calling the other national party the “Democrat Party.” Joe McCarthy did so, as did President Reagan. Newt Gingrich deliberately revived the term in the 1990s, when his pollster found that it tarnished the Democratic Party’s image in voters’ minds.

Yet many Republicans deny that they are intentionally insulting the other party.

“This is a well-known term that has been used for years and years. Our focus is on policymaking and being certain the Senate is passing the best legislation possible,” the press secretary for the Senate Republican Conference, Ryan Loskarn, said. The statement was in response to questions about the use of “Democrat” as an adjective in press releases the group has distributed in the Capitol in recent weeks.

“It wasn’t intended to be antagonistic or a jab of any kind at the Democrats,” Brian Kennedy, a spokesman for Boehner, said regarding the majority leader’s remarks on the opening day of Congress.

But other Republicans would seem to take issue with the Democrats’ chosen name.

“A gathering of Democrats is the Democrat Party, and a gathering of Republicans is called the Republican Party,” a spokeswoman to former House Majority Leader Tom DeLay (R-Texas), Shannon Flaherty, asserted.

“Their incessant whining and attempts to adjective-ize their identity is another way to fool people into associating democratic principles with the modern Democrat Party,” she continued. “Looks like our refusal to adopt their self-absorbed political syntax is giving them a post-election identity crisis.”