Television ads sponsored by a conservative group bankrolled by the Koch brothers and blasting three Florida Republican state senators for votes on public pension changes, among other issues, have sparked a war of words with liberal groups.

The Florida chapter of Americans for Prosperity, which is funded in large part by the billionaire brothers whose fortune comes from Koch Industries, this week announced it was launching a "campaign to educate" voters in three districts. The senators targeted are Charles Dean of Inverness, Nancy Detert of Venice and Greg Evers of Baker.

"These three senators voted to give taxpayer-funded handouts to billionaires, opposed giving parents the power to turn around failing schools, and voted to kill common-sense reform of the antiquated Florida pension plan ­– reforms that would have protected and honored the contracts of everyone currently in the system while protecting Florida's taxpayers moving forward," said the chapter's state director, Slade O'Brien, in a statement.