Now that President Obama has unveiled the “Buffet Rule” as the key principle behind his deficit reduction plan, one prominent Senate Republican is calling on billionaire Warren Buffet to publicly release his tax returns.

“If he’s going to be the gold standard, so to speak, in terms of what our tax policy should be, let’s look at them,” Senator John Cornyn, R-TX, said while aboard ABC’s “Subway Series with Jonathan Karl.”

Featured prominently in the Administration’s $2 trillion deficit reduction plan is the “Buffett Rule,” a controversial provision named after Warren Buffett that establishes a minimum tax on Americans making $1 million or more in income.  Ahead of the president’s proposal, Buffett penned an op-ed in the  The  New York Times  called “ Stop Coddling the Superrich,” where he argued that he should not be taxed at a lower rate than his non-billionaire staff.

Cornyn suggests the Administration’s proposed “Buffett Minimum Tax” (BMT) is really just a revamped version of the Alternative Minimum Tax (AMT) – an unpopular measure first adopted in 1969 that was designed to hit the super wealthy.

“Unless we stop this, 30 million middle income tax payers will be affected,” Cornyn said in presumed defense of the middle class.  “It’s an illusion to say we’re only going to tax the rich.”

Joining a chorus of criticism from the republican presidential field in recent days, Cornyn also hit the President on foreign policy.

“I think the president has treated our friends and allies in many instances poorly- Israel, our principal ally in the Middle East and Taiwan,” Cornyn told ABC News.  “You know the bullies around the world look at the way we treat our allies, and it emboldens them when we treat our friends poorly like this.”

Cornyn has filed a bill in conjunction with Senator Menendez (D-NJ) in response to the Obama Administration’s announcement Wednesday of $5.85 billion in arms sales to Taiwan.  The bulk of the deal involves radar and weapons upgrades for Taiwan’s 145 F-16 A/B fighters – not the newer planes Taiwan had requested. Cornyn’s the Taiwan Airpower Modernization Act of 2011 requires the United States to sell at least 66 new F-16C/D multirole fighter jets to Taiwan.

“It’s our responsibility. We gave our word,” Cornyn, a member of the Senate Armed Service Committee,  said of 1979 Taiwan Relations Act.  ”[Obama] still retains his veto power, but what we can do is keep them from sweeping this under the rug and making it go away. I think what it boils down to is they don’t want to irritate our banker, the Chinese.”

When asked about potential 2012 Cornyn, the current Chairman of the National Republican Senatorial Committee, refrained.  He said he won’t be endorsing any candidate in the primary.

“My principal responsibility is to try to get Republicans in the majority in the Senate, and I don’t want to do anything to detract from that,” he said. “I will enthusiastically support the nominee because I think it’s important for the country.”

Cornyn also refused to side with either of the two presumed front-runners, Governors Rick Perry and Mitt Romney.

“I’m not hedging that, but I would say it hasn’t really been determined yet,” Cornyn said. “I think it’s still a work in progress, because you know, sometimes things can turn on a debate or something said inadvertently, and so there’s a lot of time left till Republicans get to choose.”

For his part, Cornyn has his own campaigning to attend to. A recent shake up in Republican Senate Leadership has opened a number of positions – namely the role of Whip, which Cornyn is currently campaigning for.

“One thing you can be sure of is it’ll be a 100 percent turnout,” Cornyn joked. “You don’t come in to this job without wanting to maximize your ability to influence the process and hopefully steer the country in a better direction.”

You can watch more “Subway Series with Jonathan Karl” HERE.