Taxes for small businesses became a focal point on the campaign trail last week as Republican presidential nominee Mitt Romney attacked President Obama’s record on small business during a speech at Chantilly design company Exhibit Edge.

Romney called the Obama White House “the most anti-business administration” since Jimmy Carter, zeroing in on how the president’s proposed “Buffett rule” would hurt small businesses, The Hill reported. The rule would impose a minimum tax rate on those earning at least $1 million a year.

“What he’s done over the last three and a half years is install a series of policies that have made it backbreaking for many small businesses,” he said.

Allowing Bush-era tax cuts to expire at the end of the year, which Obama has supported — with the exception of extending the cuts for those who make less than $250,000 — would raise tax rates from 35 to 40 percent for small-business owners who are taxed as individuals, the Romney camp said.

An Obama spokesperson pointed out 98 percent of taxpayers earn less than $250,000, and letting the tax cuts expire for the wealthiest Americans would impact less than 3 percent of all small businesses. Obama has cut taxes for small businesses 18 times, including eliminating capital gains taxes on the sale of some small-business stock, the re-election campaign said.

During his speech, Romney said he would stimulate the economy by easing regulations and reducing taxes and that, “People ask me, ‘What would you do to get the economy going?’ I say, well, look at what the president’s done, and do the opposite.”

Romney’s tax plan calls for a reduction in all individual income tax rates, dropping the top rate from 35 to 28 percent and the bottom rate from 10 to 8 percent.

Obama’s tax plan would raise revenue mostly from higher-income families, while Romney’s plan would raise tax rates of low- and middle-income families, according to a Washington Post analysis of the two tax plans.

“We’re happy the priority was on small businesses,” said Chris Walters, senior manager for legislative affairs at the National Federation of Independent Businesses, the trade group that represents small businesses.

On a score card that tracks proposals affecting businesses, the NFIB gives an “F” to the parts of Obama’s 2013 budget that call for income tax increases on those earning more than $250,000.