By Shaun Boyd

(CBS4) – President Donald Trump leaves Wednesday for a series of stops around the country to rally support for tax reform as activists on both sides go to war over the issue.

READ MORE: Aurora Police: Suspected Drunk Driver Survives Crash That Killed Passenger

Americans for Prosperity Colorado — a conservative group funded by billionaires Charles and David Koch — rallied the troops in Colorado.

(credit: CBS)

“Our goal is to close those loopholes, reduce brackets, and create a simpler, fairer, flatter system for everyone,” says AFP State Director Jesse Mallory.

He says the rally is part of large-scale effort by the conservative group to ramp-up pressure on Congress. They’ve made thousands of calls, he says, mailed flyers and canvassed door to door to encourage people to lobby their lawmakers.

CBS4’s Shaun Boyd interviews Rep. Ken Buck (credit: CBS)

“There’s a poll recently done that says over three-quarters of Americans think that the system is rigged in favor of the wealthy and well-connected,” said Mallory. “And when you look at the tax code, you can see why because the average person can’t possibly understand all that.”

READ MORE: Deadly Head-On Crash On Highway 86 Happened 'Short Time' After Deputy Tried To Stop Driver, Sheriff's Office Says

But billionaires — like the Kochs — would also benefit and liberal groups are vowing to fight any reform that lowers taxes for the wealthy.

Rep. Ken Buck, a Republican who represents Colorado’s 4th Congressional District, was the keynote speaker at the rally and says everyone would see their taxes lowered.

“As for this being a tax package for the rich, that’s ridiculous. This is a middle class tax package. Will the rich benefit? Absolutely. But, if the rich don’t benefit, they’re going to take their jobs and they’re going to go to other countries,” Buck said.

Buck says he’s less worried about liberals than lobbyists, who he says will fight to keep the hundreds of carve-outs for special interests. His goal, he says, is to simplify the code so most of us won’t even need to itemize and can file our taxes on a postcard.

(credit: CBS)

“We can just check the box on a standard deduction. We can fill out four or five more lines and we can get our return and hopefully our money back,” he said.

Before Congress can take up tax reform, it has to pass a budget, raise the debt ceiling and appropriate money to keep the government open; all by the end of September.

MORE NEWS: NOAA Outlook For Early December Keeps Colorado Warm And Dry

Shaun Boyd is CBS4’s political specialist. She’s a veteran reporter with more than 25 years of experience. Follow her on Twitter @cbs4shaun.