A motley mix of staunch conservatives, anarchists, libertarians, vegetarians, gold-bugs, isolationists, drug users, 9/11 conspiracy theorists and others are donating today to the insurgent presidential campaign of Rep. Ron Paul (R., Tex.).

A group of Paul’s supporters have (perhaps appropriately) designated Guy Fawkes Day — November 5 — as Ron Paul Mass Donation Day. About 18,000 supporters of the anti-war, pro-life, anti-tax, pro-drug-legalization candidate pledged to donate $100 each today.

If it actually happens, that would give Paul, who wants to bring the troops home from Iraq and abolish the IRS and the CIA (for starters), an additional $1.8 million in a single day. It may sound laughable for a candidate given no chance of victory. But as of 7 this morning, Paul had already raised more than $500,000, according to RonPaulGraphs.com, which claims to be getting its numbers straight from the campaign’s web operation.

Paul’s supporters are credibly accused of spamming message boards and chatrooms. But the fundraising demonstrates that he has real supporters, too — a lot of them. Paul remains a fringe candidate — more than anything else, his anti-war message has made it difficult for him to find the Republican supporters he needs to win in key primaries. Yet over at Intrade.com, Paul is somehow in third place in the Republican futures markets, behind former New York City Mayor Rudy Giuliani and former Massachusetts Gov. Mitt Romney. He now leads not only Sen. John McCain (Ariz.) and former Arkansas Gov. Mike Huckabee, but also former Sen. Fred Thompson.

The big question is whether Paul can translate any of his fundraising into poll results. So far, he has failed to make a consistent, significant showing in any poll of any important state.