WASHINGTON -- California's representation in Congress, the largest in the nation, contains a mix of hawks, doves, conservatives and liberals.
Yet as Washington debates the proper role for the U.S. to play in Syria, a less ideological factor seems to influence whether members support the use of military force -- the party of the commander in chief.
A California News Service analysis of votes cast by California's current Congressional delegation dating back to the 1991 Gulf War found that members supported the use of force by presidents of their own party and opposed the use of force by presidents of the other party nearly 80 percent of the time.
And if the near-unanimous vote to authorize President George W. Bush to use force against terrorists just three days after the September 11, 2001, attack is discounted, the number rises to more than 90 percent.
The same pattern is apparent on a national scale. Congressional support for military force in Iraq, Somalia, Bosnia and Kosovo overwhelmingly came from the president's own party.
The Democrats' lackluster response to Obama's call for military action in Syria stands as a stark exception to the rule, and helps explain why the president was so quick to postpone a vote and pursue a diplomatic solution.
Only four of the California's 35 House Democrats -- and not a single Republican -- voiced approval for Obama's plan to conduct military strikes in response to Syria's use of chemical weapons.
Local Reps. Kevin McCarthy, R-Bakersfield and David Valadao, R-Hanford, are among those who have withheld a public endorsement of Obama's military strategy.
It is hardly surprising to discover partisanship in Congress, but on matters of war and peace there is an expectation that party divisions play a smaller role. While it is common for party leaders to apply pressure to their members to stick together on procedural and budget matters, it is rare to do so on votes regarding military force.
"Partisanship is less important when it comes to foreign policy because you are treading so much on very personal, very sensitive issues when you are talking about putting people in war,'' said John Lawrence, who spent nearly 40 years as a senior aide on Capitol Hill including eight years as Democratic Leader Nancy Pelosi's chief of staff.
Pelosi "will not push people very hard around the issues of war and peace,'' Lawrence said. "She views these issues as highly personal involving people's ethical, political and strategic thoughts.''
But the pattern of the California delegation over the past several decades is unmistakable; Democrats overwhelmingly support military operations proposed by Democratic presidents, while Republicans support those proposed by Republicans.
Of the votes cast by members of the California delegation who were in office during previous debates over the use of force, 75 of 97 followed party lines. And discounting the vote immediately after Sept. 11, 2001, the number is more dramatic: 66 of 73.
McCarthy and Valadao were not in Congress during the past use of force votes.
Members from both parties insisted that policy, not partisanship, determines votes in matters of war and peace.
"The decision to use force is the most difficult decision any member of Congress faces. I consider factors such as what is the threat to our security and have all diplomatic options been exhausted, not party labels," said Rep. Sam Farr, D-Santa Cruz, voicing a view expressed by a half a dozen members in interviews.
Still, Farr voted to use force only when Clinton was president.
McCarthy, the No. 3 Republican in the House, voiced a similar opinion regarding the role of partisanship.
"I don't play politics when it comes to foreign policy,'' McCarthy said on the "First Look with Scott Cox" radio show in the beginning of September.
Each conflict presents a unique set of circumstances, and the party line votes may reflect ideology as well as politics.
The mission in Somalia -- largely supported by Democrats -- began as humanitarian aid. President Clinton sent troops to Bosnia and Kosovo as part of a NATO force seeking a political settlement. The Iraq situations in 1991 and in 2002 were perceived by some as threats to American national security and were mostly supported by the Republicans. And the September 2001 terrorist vote followed a direct attack on the U.S. and received support from both parties.
"Partisanship doesn't determine whether or not members of Congress will vote for or against the use of force but it very heavily shapes their position. Today, for a Republican to support something that Obama supports would be seen by their constituents as treason, (regardless of) the content of it,'' said Adam Berinsky, a professor of political science at the Massachusetts Institute of Technology who has written extensively on public opinion toward foreign policy and war.
The risk and uncertainty that accompanies such decisions often lead members to give the benefit of the doubt to a president of their own party.
"Republicans supported George W. Bush in Iraq and Afghanistan partly out of partisan loyalty to their president, even though the wars were falling apart," said Gary Jacobson, a political science professor at the University of California, San Diego.
Rep. Dana Rohrabacher, R-Huntington Beach, was not surprised by the correlation between House member's personal views and their party's ideology.
"That's why they are in the same party, because they have the same world view,'' Rohrabacher said. "Do we have people who, for purely political reasons, oppose the president? Very, very few.''
Whether it is policy or politics, members' personal views closely match the president's if they are from the same party.
"There is a natural tendency for the party of the president to support the president," said Rep. John Garamendi, D-Walnut Grove. "And there is an even stronger tendency to support the president when it comes to issues of war.''
The California News Service is a project of the University of California's Washington Center and the UC Berkeley Graduate School of Journalism. Contact CNS at email@example.com.