Despite President Barack Obama's appeal for civility, history suggests any move toward cooler political rhetoric after the Arizona shootings will soon fade.
An early test will come Jan. 25, when some lawmakers are asking Democrats and Republicans to sit side by side for Obama's State of the Union speech, rather than splitting the House chamber by party as usual.
Initial reactions to that idea on Capitol Hill were not encouraging, especially from the Republican side. A spokesman for House Speaker John Boehner, R-Ohio, said House members may "sit where they choose."
Senate Minority Leader Mitch McConnell, R-Ky., had no comment on the suggestion, which was offered by Democratic Sen. Mark Udall of Colorado. Majority Leader Harry Reid, D-Nev., signaled he might be open to the idea but wanted more discussion. House Minority Whip Steny Hoyer, D-Md., embraced it.
In a sometimes-emotional speech Wednesday night in Tucson, Obama implored Americans to reflect on the fatal shootings at Democratic Rep. Gabrielle Giffords' outdoor forum, but "not on the usual plane of politics and point-scoring and pettiness that drifts away with the next news cycle."
A lack of civility did not cause the tragedy, he said, but "only a more civil and honest public discourse can help us face up to our challenges as a nation."
The White House on Thursday said it was interested in Udall's proposal to have Democrats and Republican intermingle when they sit for this month's big speech by Obama.
"The choreographed standing and clapping of one side of the room — while the other side sits — is unbecoming of a serious institution," Udall said in a letter. As the nation reels from the six fatalities in Tucson and the severe wounding of Giffords, he said, Congress has a chance "to bring civility back to politics."
House Republicans have rejected the Democrats' request to postpone next week's vote to repeal the Obama-backed health care law, the focus of harsh political commentary, and occasional violence, for the past two years.
Looking back at the effects of other recent tragedies
National tragedies in recent years have led to calmer political rhetoric only briefly, if at all.
Leaders of both parties vowed to unite the nation after an anti-government militia movement sympathizer killed 168 people by bombing a federal building in Oklahoma City in 1995. Seven months later, a partisan budget impasse led to a temporary government shutdown. The public mostly blamed House Republicans, and the incident helped catapult President Bill Clinton to re-election.
In 2001, a few hours after the Sept. 11 terrorist attacks, lawmakers from both parties sang "God Bless America" on the Capitol's steps. "Democrats and Republicans will stand shoulder to shoulder to fight this evil," said House Speaker Dennis Hastert, R-Ill.
But the parties returned fairly quickly to quarreling and strong-arm tactics on domestic issues, then split over the Iraq war. Hastert oversaw a GOP push to add a prescription drug benefit to Medicare in 2003. It culminated in a much-criticized predawn House vote in which the roll call was held open for hours while party leaders pressured colleagues to vote yes.
If anything, partisanship has worsened since then. Last year's health care law was passed despite unanimous Republican opposition. Giffords, who voted for the bill, received threats, saw her district office vandalized and said she worried about the consequences of menacing debate.
The House appears more sharply divided now. The Republicans' 63-seat gain in last fall's elections came mainly at the expense of moderate Democrats, making the Democratic caucus smaller but more liberal.
"The parties, especially in the House, are much more divided now," said Emory University political scientist Alan Abramowitz. And with a few congressional Republicans defeated in last year's primaries by tea party candidates, Abramowitz said, some GOP lawmakers will not want to risk being seen as willing to work with Democrats.
Last week, the Washington-based "Civility Project" disbanded after only three of Congress' 535 members signed a pledge to treat their adversaries with respect.
Lanny J. Davis, a Democratic lawyer and co-founder of the bipartisan project, said Thursday that lawmakers in both parties "want to reserve the right to be angry and uncivil."
Davis, who counseled the Clinton White House, said irresponsible partisan sniping won't stop until leaders of both parties reprimand abusers from their own side, not their opponents'. He said Obama should publicly ask liberal commentators such as MSNBC's Keith Olbermann to stop attacking conservatives such as Fox News' Bill O'Reilly.
'Sister Souljah' moments
"If there is going to be a change, there has to be more Sister Souljah moments," Davis said. He was referring to a 1992 campaign speech in which Clinton angered some blacks, an important Democratic base, by criticizing violent and racially tinged hip-hop songs and their singers.
Obama won widespread praise for Wednesday's speech in Tucson. But he has been known to indulge in partisan digs himself. He regaled audiences last year with a parable about unhelpful Republicans, standing on the sidelines and "sipping on a Slurpee," while Democrats tried to pull the economy from the ditch where the GOP drove it.
And last February, Obama hosted a bipartisan health care summit that had virtually no bipartisan warmth.
When Sen. John McCain, whom Obama had defeated to win the presidency, condemned the overall health care debate, Obama sharply reminded him, "We're not campaigning anymore. The election's over."
And now the 2010 election is over, with Obama's party suffering huge losses. Republicans feel emboldened, Democrats are surly, and a horrific shooting in Arizona may do little to change the dynamics.