A super PAC aligned with the conservative Koch brothers has spent millions on advertising in tight Senate races in Nevada and Ohio, and elsewhere after the billionaire industrialists announced they would not bankroll Donald Trump's presidential campaign. The Koch brothers and the conservative donor network they oversee had planned to funnel hundreds of millions of dollars to politics and policy in 2015 and 2016, putting them on par with both the Democratic and Republican parties and positioning the group to wield unparalleled influence on conservative campaigns. The group has so far spent $19.3 million in a handful of states, according to NBC news. [ Reid to Koch Brothers: Stay Out of Nevada ] Freedom Partners Action Fund, a super PAC financed by the Charles and David Koch network, bought $2.7 million television and digital ads in Ohio, where incumbent Sen. Rob Portman, a Republican, is locked in a dead heat against Democrat Ted Strickland in one of the year's most competitive Senate races, according to media reports . [ Memo to Campaigns: Don't Leave Ad Scripts on Capitol Benches ] The group announced last week that it plans to spend $1.2 million on advertising in Nevada, where Democrat Catherine Cortez Masto is running against Republican Rep. Joe Heck to replace Senate Minority Leader Harry Reid. The race is rated Tossup by the Rothenberg & Gonzales Political Report/Roll Call . The super PAC is also reportedly in the process of reserving television ad time in Florida after Republican Sen. Marco Rubio announced he would run for re-election. Contact Akin at stephanieakin@rollcall.com and follow her on Twitter at @stephanieakin . Get breaking news alerts and more from Roll Call on your iPhone or your Android.