Attorney Jon Hulburd (D), who had quietly been running for Rep. John Shadegg's (R-Ariz.) seat before Shadegg's retirement announcement today, could be more formidable than anybody thought.

A Democratic source tells The Hill that Hulburd will announce raising more than $300,000 in the fourth quarter -- a tall sum for a House challenger.

Hulburd also has personal wealth and is able to write a check for his campaign. The source said all the money raised in the fourth quarter, though, came from donors.

Democrats saw their 2008 candidate, attorney Bob Lord, crash and burn at the end of his campaign. Shadegg's 56-42 McCain district will be tough, but having a moneyed candidate in an open seat means anything can happen.

Here are some Republicans who might seek the seat:

-Former Shadegg Chief of Staff Sean Noble

-State Treasurer Dean Martin (who could also run for governor)

-State Sen. Pamela Gorman

-Former Arizona State University quarterback and NFL free agent Andrew Walter

-State Sen. Jim Waring

-State Rep. (and former Speaker) Jim Weiers

-State Rep. Sam Crump