JEFFERSON CITY, Mo. – The tax cut fight of 2014 is different in many ways from the tax cut fight of 2013.

This time, the debate over an override of a likely veto from Democratic Gov. Jay Nixon is compressed into just a couple of weeks instead of an entire summer, and the tax cut itself has been scored to be about half the size of the tax cut lawmakers considered last year.

But perhaps the biggest difference between the fight over 2013’s House Bill 253 and 2014’s Senate Bill 509? Republicans appear to be sticking together.

House Majority Floor Leader John Diehl, R-St. Louis, has taken the lead on Senate Bill 509’s messaging effort. Even before taking the vote, Diehl stressed a united show of force from Republicans in support of the bill, and used the support of Republicans who opposed last year’s tax cut as his prime examples.

The strategy from Diehl, the incoming House Speaker, appears to be focusing more under the dome and less on conservative talk radio – and it might just be working. Diehl said he believes all Republicans are on board to vote to override a gubernatorial veto. Nixon has until May 1 to take action on the bill. Diehl said the only challenge would be the logistics in making sure all 108 members of the Republican caucus appear for the vote.

Last year, even House Speaker Tim Jones was critical of legislators who would vote against HB 253 – noting political consequences for members of what conservative groups began to call the “flimsy 15.” Those challenges did not surface, despite the threats from outside groups.

“I’m sick and tired of herring that crap, the ‘flimsy 15,'” Diehl said at a news conference ahead of the vote. “It’s over. People are committed. We’re united as a caucus.”

On Thursday, Diehl and Jones were joined by a dozen businessmen from across the state supporting the bill, which offers a 25 percent deduction for business owners on their personal income tax returns, as well as a .5 percent tax reduction for most other Missourians.

“It’s very important that we put out the message of how this is a tax cut which benefits businesses in the state,” he said. “This is not for lawyers and lobbyists as the governor is trying to scare people into thinking. It is for real businesses across the state.”

Nixon has claimed a fatal flaw in the law that he says would effectively eliminate the taxes on income above $9,000, which, if true, could blow a $4.8 billion hole in the state’s revenue. The claim sparked a strain of news reports across the state, but the legal community is split. Nixon’s office has provided an opinion supporting his position from a Washington University professor, and Diehl has provided a legal opinion from former Missouri Chief Justice William Ray Price – a member of Diehl’s law firm – supporting his claim.

“The direct language of this bill crashes a giant hole in the future of this state,” Nixon said.

Aside from the disputed claim about whether the bill would actually eliminate the income tax, Nixon has channeled his 2013 playbook on education. He pointed to numbers put together by the Missouri School Board Association that claim significant cuts to K-12 education. But those numbers do not account for the increased K-12 education spending in this year’s budget. On Wednesday, House Speaker Pro Tem Denny Hoskins’ office began circulating their own numbers accounting for the funding increase, as well as the increased revenue required in order for SB 509’s tax cut to go into effect.

“I hope it is helpful if you receive calls from your superintendents,” Hoskins wrote in a memo to colleagues, claiming a $47 million increase in education funding, compared to the Missouri School Board’s claim that the revenues will be reduced.

Unlike last year, schools and higher education leaders have been more reluctant to weigh in as vocally on the fight.

If (or when) Nixon vetoes the bill, Republicans in the Senate would first be tasked with starting the process. Senate President Pro Tem Tom Dempsey said on Tuesday he believed he has the votes to do so. Then it would be sent to the House, where Republicans need the support of at least one House Democrat. Rep. Jeff Roorda, a Democrat running in a competitive state Senate seat against Republican Rep. Paul Wieland, initially voted in favor of the bill.