Nov. 9 (Bloomberg) -- Representative Anh “Joseph” Cao has spent his first year in the U.S. House being the Democratic majority’s most reliable Republican. He underscored that role when he became the only member of his party to vote for the health-care bill the chamber passed.

The plan to overhaul the nation’s health-care system was approved 220-215 late on Nov. 7, with 39 Democrats crossing party lines to oppose it.

Cao, the first Vietnamese American to serve in Congress, has cut against the grain throughout his political career.

He won his seat last year in a majority-black, New Orleans-based district that gave 75 percent of its presidential votes to the Democratic candidate, Barack Obama. He ousted the indicted Democratic incumbent, William Jefferson, who was later convicted of soliciting bribes.

Since taking office, Cao has been the Republican lawmaker most likely to split with his party, according to Congressional Quarterly, which tracks legislative voting patterns. He has bucked his party more than one-third of the time on votes considered gauges of party unity, according to CQ.

Cao, 42, is considered the most endangered Republican incumbent in 2010, according to CQ, the Cook Political Report and the Rothenberg Political Report, three publications that track congressional races.

Democratic political consultant Peter Fenn said Cao’s health-care vote will help his re-election effort.

“It puts you on the map,” Fenn said. “I’d rather be on the map as a profile in courage. If he doesn’t make it, at least he’s cast a vote that he’s proud of.”

Family Flees

Cao, whose last name is pronounced “Gow,” was born in Vietnam and fled with most of his family when he was 8, shortly after communists captured what was then Saigon in 1975. His father, an officer in the South Vietnamese Army, was in a North Vietnamese prison camp before eventually joining the family in the U.S.

Cao graduated from Baylor University in Waco, Texas, with a degree in physics and began studying for the priesthood. Later, he moved to New Orleans to get a law degree from Loyola University. He opened a law firm in the city, got married, and entered politics following Hurricane Katrina. The 2005 storm destroyed both his home and his law office.

After running unsuccessfully for the Louisiana House of Representatives as an independent, he joined the Republican Party and launched his challenge against Jefferson.

‘Partisan Wrangling’

In a statement on his Web site concerning his vote on the health-care bill, Cao said he “listened to the countless stories” from constituents “whose health-care costs are exploding -- if they are able to obtain health care at all. Louisianans need real options for primary care, for mental health care, and for expanded health care for seniors and children. I have always said that I would put aside partisan wrangling to do the business of the people.”

The House bill would require all Americans to get coverage, impose new restrictions on insurers and set up a public program to compete with private companies. The spotlight on the issue now shifts to the Senate, which is considering its own version of the legislation.

Cao said an abortion-related restriction added to the House bill during final debate on it was crucial to his vote for the measure. “Taxpayer dollars will not go to supporting elective abortions, and for thousands of my constituents, this was a top priority,” he said in his Web site statement.

In previous votes this year in which he broke with most other House Republicans, Cao supported Democratic proposals to broaden the reach of the federal hate-crimes legislation and to expand health insurance for children.

Among the 39 Democrats who opposed the health-care bill, 29 of the “no” votes came from members of the Blue Dog Coalition, which supports cuts in federal spending, and the pro-business New Democrat Coalition.

Eight of the 20 most vulnerable House Democrats in 2010, as rated by CQ, Cook and Rothenberg, were among those opposing the legislation.

To contact the reporter on this story: Jonathan D. Salant in Washington at jsalant@bloomberg.net

Last Updated: November 9, 2009 00:01 EST