Third-term Rep. Jon Porter, R-Nev., has more than $770,000 cash on-hand going into next year's contest against likely Democratic challenger Robert Daskas.
Daskas raised more than $145,000 as of Sept. 30, though he entered the race less than two weeks into September.
The campaign finance reports covering the third quarter of 2007 were due Monday night to the Federal Election Commission.
Democrats plan to target the 3rd Congressional District next year.
The district, consisting of areas surrounding Las Vegas to the east, west and south, is closely split between Democrats and Republicans. Last year Democrat Tessa Hafen, a former aide to Senate Majority Leader Harry Reid, D-Nev., lost to Porter by less than 4,000 votes.
Daskas is a Clark County chief deputy district attorney and is prosecuting Darren Mack, the man accused of killing his estranged wife and later shooting their divorce lawyer.
The trial is expected to begin this week in Las Vegas and Daskas has said he will step down from the D.A.'s office and begin campaigning once it's over.
Porter raised $284,445 during the quarter, bringing his election-to-date total to nearly $980,000. Daskas raised a total of $146,350 and ended the quarter reporting that same amount as cash on-hand.
Also running for the Democratic nomination is accountant Andrew Martin, who raised $11,825 in the quarter and ended up with $88,280 cash on-hand.
Porter has represented the 3rd Congressional District since it was created in 2002 after congressional redistricting following the 2000 census.
In Nevada's rural 2nd Congressional District, first-term Rep. Dean Heller, R-Nev., raised about $161,000 in the quarter and ended up with $597,000 cash on-hand, but debts of more than $380,000.
Heller won a close race last year against Democrat Jill Derby but has not yet drawn a declared Democratic opponent this time around.
In the 1st Congressional District of Las Vegas, Democratic Rep. Shelley Berkley reported raising just over $280,000 with more than $1.2 million cash on-hand in her campaign for a sixth term.
She's faced no more than token Republican opposition in recent years.