Billionaire US businessman Charles Koch has spent a fortune supporting the Republican Party.
Billionaire US businessman Charles Koch has spent a fortune supporting the Republican Party. Bo Rader

Republican Kochs take $500m aim at Democrats

TWO billionaire brothers in the US who have poured a fortune into the Republican Party have pledged to spend $A500million in an attempt to thwart the Democrat surge in this year's mid-term elections.

Charles Koch, 82, and brother David, 77, have ordered their network of conservative activists and donors to radically broaden their political scope in the lead-up to the elections in order to safeguard Republican majorities in the House and Senate.

About 550 Koch donors met at a five-star Indian Wells resort last weekend to discuss their plans and the tricky political climate faced by Republicans.

The Koch brothers, who have invested in a network of charitable organisations committed to supporting Republican causes and candidates, are owners of Koch Industries.

It is the second-largest privately run business in the US.

Among other things, they own oil refineries in Texas, Alaska and Minnesota.

They also own or control some 6400km of pipeline.

The Koch network, one of the most powerful conservative groups in the US, plans to spend the half a billion dollars to elect Republican candidates and promote conservative causes.

This is 60 per cent more than its spend during the 2016 presidential cycle, and also more than the combined resources spent by the Republican National Committee, the National Rifle Association and the Chamber of Commerce.

The Koch network's 2018 investment includes $A25million to help sell the recent tax overhaul to sceptical voters through public rallies, phone campaigning and paid advertising.

"My challenge to all of us is to increase the scale and effectiveness of this network by an order of magnitude, by another tenfold on top of all the growth and progress we've already made,” Charles Koch told donors.

"If we do that, I'm confident we can change the trajectory of this country.”

Only those who had donated $A125,000 or more to the network last year were invited to the event.

Among Koch donors there is believed to be heavy frustration with US president Donald Trump and the slew of controversies he has found himself in.