Rep. Anh “Joseph— Cao (R), who is viewed by many race watchers as the most vulnerable incumbent of the 2010 cycle, more than doubled his first-quarter fundraising between April 1 and June 30 thanks in no small part to an uptick in donations from his fellow Republican colleagues.

After raising less than $150,000 during the first three months of the year and reporting an unimpressive $61,000 in the bank on March 31, Cao on Wednesday reported $370,000 in receipts in the second quarter and almost $340,000 in cash on hand as of June 30.

While his first-quarter report included donations from just a handful of fellow Republican lawmakers, Cao’s second-quarter report was boosted by checks from more than 15 Republicans. House Minority Leader John Boehner (Ohio) matched his $5,000 donation during the first quarter with another $5,000 donation in the second quarter, while House Minority Whip Eric Cantor (Va.) gave Cao $10,000 and National Republican Congressional Committee Chairman Pete Sessions (Texas) cut the Louisiana Congressman a $2,000 check.

As the first Vietnamese-American Member of Congress, Cao has become a star in Vietnamese communities across the country, as well as a symbol of hope for Republicans after his upset victory last cycle in his overwhelmingly Democratic New Orleans-based district.

Cao beat scandal-plagued Rep. William Jefferson, who is black, in a district where the African-American population is 64 percent. He won by fewer than 2,000 votes against Jefferson, who is now on trial for federal bribery and corruption charges.