Republican state auditor nominee Tom Schweich has reported his first hefty donation since winning his party's nod a month ago. David Humphreys, co-owner of Tamko Building Products in Joplin, wrote a check to Schweich this week for $50,000.

Humphreys had given Schweich $10,000 during his primary battle against state Rep. Allen Icet of Wildwood.

Humphreys and his mother Ethelmae Humphreys are among the state's -- and nation's -- largest donors to conservative candidates and causes. They've distributed at least $245,000 just since January 2009, according to the nonpartisan Center for Responsive Politics, which tracks campaign donations.

The Humphreys have already given the federal maximum to the Republican nominee for the U.S. Senate, Roy Blunt. But since there are no state donation limits, Schweich's Democratic target -- state Auditor Susan Montee -- says she is expecting her GOP rival to benefit from some major largesse from donors like the Humphreys.

Which helps explain what Montee is getting fundraising help from Gov. Jay Nixon, the titular head of the Missouri Democratic Party. He appeared with Montee on Tuesday at the state AFL-CIO convention downtown. 

Schweich said today that the Humphreys donation reflects the fact that "there are a lot of Republicans who feel that winning the state auditor's office is a high priority."