Smoking gun in IRS scandal? Rep. Darrell Issa says he's close.

For all intents and purposes, the only politically relevant fact in the IRS scandal is the still-unanswered question of who, ultimately, decided to harangue tea party groups with reams of extra paperwork during the 2012 election season.

The Obama administration has suggested that a few "rogue agents" in one Cincinnati office were to blame. And the evidence, so far, has appeared to at least partly support that claim. Media reports have painted a picture of an office overwhelmed by the task of sorting through which tax-exempt groups were actually playing according to the arcane rules of US tax law and which were not. Disproportionately, it seems, conservative groups got the runaround. 

Yet what has been lacking from the Republican viewpoint is — if not a smoking gun, precisely — then at least a steaming teacup. Where was the evidence that "rogue agents" were, in fact, dutiful subordinates, carrying out a clear plan of political recrimination that had its origins all the way back in Washington?

On Sunday, the House Republican tasked with carrying out that chamber's investigations offered his strongest claim yet that the IRS scandal was part of a broader Obama administration conspiracy.

"As late as last week, the administration's still trying to say there's a few rogue agents in Cincinnati, when in fact the indication is they were directly being ordered from Washington," said Rep. Darrell Issa (R) of California on CNN's "State of the Union."

His evidence? Partial transcripts of the closed-door testimony to Congress of IRS employees in the Cincinnati office.

According to one transcript, an employee was asked if the scandal could be the work of a few local rogue agents. "It's impossible," the employee said. "As an agent we are controlled by many, many people. We have to submit many, many reports. So the chance of two agents being rogue and doing things like that could never happen."

The interrogator then asked: "With respect to the particular scrutiny that was given to tea party applications, those directions emanated from Washington, is that right?"

"I believe so," the IRS employee said.

Yet Issa and fellow Republicans were careful not to go too far Sunday. Scandals are Washington's political potboilers, after all, and the authors try to leave every Sunday morning chapter on a cliffhanger.

When Candy Crowley, the host of "State of the Union," pushed Representative Issa for a clearer link — evidence of a direct order from Washington — he said his committee was following a paper trial to try to establish facts, but the White House had not yet supplied subpoenaed documents.

It is part of an established Washington tradition. Congressional investigators from one party ask presidents for reams of documents in the name of transparency, presidents of the other party tell Congress to buzz off, saying Congress is on a political witch hunt, and the scandal survives for another week.

In the meantime, Issa was careful not to specifically accuse anyone of anything — while making it clear that he doesn't trust the Obama administration.

He cited Lois Lerner, the head of the IRS division on tax-exempt organizations, who last month refused to answer questions posed by Issa's committee, invoking her constitutional right not to incriminate herself.

"The reason that Lois Lerner tried to take the fifth is not because there is a rogue in Cincinnati, it's because this is a problem that was coordinated in all likelihood right out of Washington headquarters and we're getting to proving it," he added.

At one point, he even called White House spokesman Jay Carney a "paid liar."

"My gut tells me that too many people knew that this wrongdoing was going on before the election," he said. "And at least by some sort of convenient benign neglect, allowed it to go on through the election — allowed these groups, these conservative groups, these, if you will, not friends of the president, to be disenfranchised through an election."

The idea that the Obama administration has played the part of an enabler, allowing a vindictive partisan culture to flourish in the American bureaucracy, was echoed by other Republicans Sunday morning.

"The culture of the president calling tea party groups terrorists and tea-baggers, and that entire culture has been cultivated by the president and his people, and everyone has been following," said Republican National Committee chairman Reince Priebus on "Fox News Sunday."

Added Republican strategist Karl Rove on ABC's "This Week": "People sitting in Cincinnati, Laguna Niguel, Baltimore, and Washington, D.C., listen to people like Sen. Max Baucus, Sen. Chuck Schumer, President Obama. When President Obama goes out in 2010 and calls these groups ‘a threat to democracy,’ he’s blowing a dog whistle.”

Rove also said further investigation would reveal further discrimination.

“We’re going to find that the IRS targeted conservative political groups, not liberal groups, and that they targeted specific individuals,” he said.

Democratic strategist David Plouffe, also on "This Week," rebutted the charges.

“There’s been no suggestion — the [IRS] inspector general said there was no politics involved in this,” he said. “This was not an effort driven by the White House. It would be the dumbest political effort of all time.”

At least on that point, perhaps, both sides can agree.