A bid by the son of longtime House Majority Leader Dennis Hastert to defeat the man who replaced his father is far from a sure thing, but if nothing else, a respectable showing by the younger Hastert could keep the incumbent, Bill Foster, from replenishing his personal bank account.

The abrupt resignation of the elder Hastert in 2008 triggered a special election that was characterized by the exceptional reliance on personal funds: Businessman and scientist Bill Foster loaned his campaign two million dollars to defeat Jim Oberweis, a dairy-products magnate who blew through $3.8 million in personal funds vying for the seat–after a string of failed bids for the Senate and Illinois governorship.

Foster, a Democrat in a heavily Republican district, retained his seat in the regular 2008 election and recouped half of his self-funding, then loaned himself another $45,000 earlier this year. Now, the Hastert family is back in the game, with Ethan Hastert keeping him on guard by raising $313,000. Foster had a much bigger take, at $1.1 million, but his campaign committee still owes him $900,000 between last year’s debt and this year’s smaller outstanding loan.

Foster is the 18th-richest member of the House, according to a Center for Responsive Politics analysis of personal financial disclosures.