This article first appeared in the St. Louis Beacon, July 2, 2013 -  St. Louis County Executive Charlie Dooley, a Democrat, capped off a brisk fundraising period with $100,000 check from retired financer Rex Sinquefield.

Missouri Ethics Commission reports show that Sinquefield gave Dooley $100,000 on June 30, the final day of the July fundraising quarter. The contribution showed up on the MEC website on Tuesday.

Dooley's full report isn't due until July 15.

Sinquefield has been a prolific donor to Dooley for years, giving Dooley over $240,000 since 2009, including this latest check.

Dooley even nabbed big donations from Sinquefield in the 2010 election cycle, when he faced Republican Bill Corrigan.

Sinquefield has rarely discussed why he is such a strong supporter of Dooley.

Sinquefield – by far the state’s most generous political donor – has donated primarily to Republican candidates. Many Democratic-leaning groups have been sharply critical of his efforts to curb teacher tenure and get rid of the state’s income tax, among other things.

Sinquefield has also donated generously to Democrats other than Dooley in recent years. He’s given sizable donations to Attorney General Chris Koster, St. Louis Mayor Francis Slay and state Sen. Jamilah Nasheed, D-St. Louis, among others.

Sinquefield's donation comes after Dooley's brisk fundraising in May and June. Including Sinquefield’s donation, Dooley has taken in over $196,000 in donations of $5,000 or more since the beginning of May.

Dooley may face a Democratic primary challenge next year from Councilman Steve Stenger, D-Affton. Stenger had plenty of money left after his re-election victory in 2012 – and currently has about $179,018.67 on hand according to his April fundraising report.

Rex Sinquefield is a donor to the St. Louis Beacon.

Send questions and comments about this story to feedback@stlpublicradio.org.

Got a news tip? Send it to Jason Rosenbaum.