Here’s the latest on the fascinating ebb and flow of fundraising by the Blue Dog Coalition — those fiscally conservative Democrats who have been attracting so much attention for their out-size influence on the health care debate.

We told you earlier about the Dogs’ PAC and its impressive haul for the first half of the year, which averaged $176,000-a-month. But we noted more recently that the July take dropped somewhat mysteriously to $27,000. Now newly released disclosures reveal an August total of $45,500 ($31,500 from other PACs). And part of that modest increase from July is attributable to a pair of $5,000 donations from unlikely sources.

The first came from a group listed in the Blue Dog PAC’s filing as simply “MPP Political Fund” of Washington, DC; this fund had previously given the Dogs $1,000 contributions in 2006 and 2008. A bit of reporting revealed that this PAC is the political arm of the Marijuana Policy Project, a tax-exempt organization dedicated to “reforming U.S. marijuana laws” and replacing pot prohibition with “a sensible system of regulation.”

We checked — the donations were cash, not in-kind contributions.

Why would such an organization contribute to one of the more conservative coalitions in Congress? Bruce Mirken, MPP’s spokesman, told the Center, “marijuana policy reform is very much a non-partisan issue. There are some Blue Dogs who have been quite good, such as Mike Thompson of California.” Thompson is a former treasurer of the Blue Dog PAC. Mirken adds that his organization gives donations anywhere they see “potential support or constituencies where we hope to make inroads.” The Almanac of American Politics 2010 says that Thompson’s Congressional district includes Humboldt County, “known for its quality marijuana fields,” and further notes that “the local economy relies heavily on the product.” Still, as of yet, the Blue Dogs have not publicly adopted marijuana decriminalization as one of their health care reform principals. Thompson’s office declined to comment.

A second surprising donation came from another previous donor making its first contribution of the 2010 cycle: the International Brotherhood of Electrical Workers. While the AFL-CIO — of which IBEW is a prominent member — has been a consistent voice demanding a public option in any health care bill, this IBEW contribution has gone to the Democrats most vocally skeptical of such an option. Jim Splaine, a spokesman for IBEW, told the Center that while IBEW’s position on health care is in “full accord” with their AFL-CIO brethren, the union pragmatically feels that the Blue Dogs in office are better options than the conservative Republicans who would likely win those GOP-leaning districts otherwise. Still, he cautioned that as the health care debate “progresses and options harden, we’ll have to re-evaluate where we stand.”

As for the overall August numbers, the Blue Dogs once again found the health care sector ($9,000) and financial services sector ($10,000) to be their most generous donors.

The Blue Dogs did not respond to a request for comment.