JEFFERSON CITY -- Joplin businessman David Humphreys and his family have donated $900,000 this year to the campaign of Republican lieutenant governor hopeful Brad Lager.

The latest donation came today, with Humphreys giving Lager $50,000 for his quest to knock off incumbent Republican Lt. Gov. Peter Kinder in tomorrow's GOP primary.

Humphreys, who is president and CEO of Tamko Building Products, has personally donated $550,000 to Lager's campaign. David's mother, Ethelmae Humphreys, donated $250,000, and his sister, Sarah Atkins chipped in another $100,000.

Humphreys was a prominent donor to Kinder until last year. He publicly criticized the lieutenant governor after news broke about Kinder's previous ties to a former stripper and Penthouse Pet.

Another former Kinder donor, retired investor Rex Sinquefield, gave Lager $385,000 last month. On Friday, Lager received $25,000 from St. Joseph-based Herzog Contracting Corp. Last month the company gave him $250,000.

That means five donors -- the Humphreys family, Sinquefield and Herzog -- have donated more than $1.5 million to Lager.

Lager is also getting help from a nonprofit called Better Government for Missouri. The organization has donated $300,000 to a political committee running mail and television ads attacking Kinder.

Despite the money, Kinder is still favored to win in tomorrow's Republican primary. A recent poll conducted by Mason-Dixon Polling & Research for the St. Louis Post-Dispatch found Kinder with a 47-21 lead over Lager, with a fourth of the respondents undecided.

Another poll, released today by Public Policy Polling, has Kinder up 42-30.

Kinder also got some financial help of his own from St. Louis businessman Sam Fox, who on Friday donated $30,000 to his campaign.