Tony Raimondo has contributed $450,000 to his own U.S. Senate campaign, meaning his chief opponent in the Democratic primary is now allowed to accept larger amounts of money from individual donors under the so-called "millionaire's amendment."

Scott Kleeb is eligible to take $6,900 from individuals, three times the $2,300 limit, under a federal law that took effect in the 2003-04 election cycle and is meant to level the playing field in big-money races.

Kleeb spokesman Joe Zepecki said Sunday that just because Kleeb can raise $6,900 at a pop doesn't mean he'll do it. Zepecki said Kleeb's campaign has been built mostly on smaller contributions from some 1,500 individuals.

But in an e-mail to supporters Sunday, Kleeb asked donors to double their contributions.

Kleeb writes that his campaign needs to increase its ad buys for the closing days of the primary campaign to keep pace with Raimondo's TV spending.