Louisiana GOP Sen. David Vitter raised just more than half a million dollars in just more than five weeks since July 1, according to pre-primary fundraising reports released Monday.

Vitter’s total was enough to more than double the total raised by his top Democratic opponent, Rep. Charlie Melancon, who pulled in just $233,000 over the same time period.

Vitter’s fundraising dominance over Melancon during the pre-primary period is the continuation of a trend that has dogged Democrats in the Bayou State race since Melancon decided to challenge the first-term Senator. In fact, Vitter’s $508,000 raised during the pre-primary period was nearly $100,000 more than what Melancon raised during the three month period from April 1 to June 30.

Vitter had just less than $5.4 million on hand for his campaign on Aug. 8, while Melancon had $2.2 million at the end of the pre-primary reporting period.

Vitter faces two opponents in the Aug. 28 Republican primary, with the more serious of the two being Chet Traylor, a former Louisiana Supreme Court justice who joined the contest just before the July 9 filing deadline. Vitter is still heavily favored to win his party’s nomination, but he’s also been forced to at least spend real money on the contest. He spent $637,000 from July 1 to Aug. 8.

Melancon’s campaign reported spending $353,000 during the pre-primary reporting period.