Sen. Marco Rubio was a day late and $8 billion short.

As part of his political comeback since his lenient position on immigration antagonized the conservative base, the Florida Republican introduced the “Obamacare Taxpayer Bailout Prevention Act.”

The idea, a back-door way to repeal the health-care law, was to get rid of the “risk corridors” and reinsurance that protect health insurers from big losses. The idea caught on: House Republican leaders floated the idea of linking it to this month’s debt-limit talks (which means they would again threaten a U.S. debt default if Obamacare isn’t dismantled), and the House Oversight and Government Reform Committee made Rubio the featured witness at a hearing on the matter Wednesday.

But the day before Rubio’s star turn, the Congressional Budget Office reported that the “bailout” actually would be a bonanza for the government. In a report that was otherwise unhelpful to the health-care law, it said risk corridors would bring the Treasury net proceeds of $8 billion over the three years they are in existence.

Meanwhile, health insurers warned that Rubio’s legislation would lead to the government-run health-care system that most alarms conservatives. And there was the awkward fact that the risk corridors were the same mechanism Republicans used in the 2006 prescription-drug legislation.

1 of 11 Full Screen Autoplay Close Skip Ad × 10 myths about Obama (that people actually believe) View Photos We’ve all heard them: Misinformation about President Obama has a penchant for spreading like wildfire. The Post’s Swati Sharma attempts to set a few matters straight. Caption We’ve all heard them: Misinformation about President Obama has a penchant for spreading like wildfire. The Post’s Swati Sharma attempts to set a few matters straight. We’ve all heard them: Misinformation about President Obama has a penchant for spreading like wildfire. Dana Milbank offers a few answers for the reasons, as he characterizes it , that the Kenyan born Muslim raised in a madrassa president somehow attracts lies and rumors that are far from the truth. As for the rumors themselves, we have compiled a list that aren't the most outrageous but have a surprising base of believers. Win McNamee/Getty Images Buy Photo Wait 1 second to continue.

Committee Chairman Darrell Issa (R-Calif.) had a solution to such problems: He would not have Rubio face questions. There had been a plan for Rubio to field questions from Issa and his Democratic counterpart, Rep. Elijah Cummings (Md.), but Issa announced that Rubio would leave after making his statement, saying, “It is not customary to interview members of the House or the Senate.”

Particularly when their testimony has been overtaken by events.

Cummings had planned to ask Rubio about his claim on CBS’s “Face the Nation” last month that he opposed expanding Medicaid coverage to 850,000 Floridians under Obamacare because the state would “get stuck with the unfunded liability.”

Unfunded? In fact, the federal government pays 100 percent of the Medicaid expansion cost in the first three years, and 90 percent after that.

Rubio’s fact-free approach to Obamacare is puzzling because plenty of damning things can be said about the health-care law that are perfectly accurate: It does little to curb entitlements, it disrupts insurance plans for millions, it leaves 31 million Americans without coverage and, as the CBO forecast, it would take the equivalent of 2.3 million full-time workers out of the workforce.

Yet the law’s opponents seem to have an uncontrollable urge to make stuff up. Issa, a frequent offender, began Wednesday’s hearings by claiming, falsely, that the CBO had said 2.5 million jobs would be lost.

I went from Issa’s hearing in the Rayburn building to a Ways and Means subcommittee hearing in the Longworth building. The topic was different — this one was about the IRS targeting conservative groups — but the no-fact zone was still in force.

There is ample evidence of mismanagement at the IRS that led conservative groups’ tax-exempt applications to be delayed. It’s disturbing that the overwhelming number of groups targeted were conservatives — and e-mails from some IRS workers indicate an inappropriate concern about public perception. There also are questions about whether the IRS’s new guidelines are too restrictive.

But Charles Boustany (R-La.), the subcommittee chairman, went well beyond that, disputing President Obama’s claim that no corruption has been found at the IRS. “Now this committee has actually investigated the matter to a significant degree and found otherwise,” he said.

That’s a serious charge: A House subcommittee chairman is alleging criminal conduct.

I checked with Ways and Means staff members and was told that Boustany did not intend to make such an allegation.

It wasn’t just him. Dave Camp (R-Mich.), chairman of the full committee, disputed Obama’s claim that the targeting occurred because workers thought the guidelines were “confusing.” Said Camp: “Nowhere in our investigation have we found that to be the case.”

Nowhere? How about in the May 3 e-mail from Treasury’s deputy inspector general for investigations? He said he had examined 5,500 e-mails related to the targeting and “there was no indication that pulling these selected applications was politically motivated. The e-mail traffic indicated there were unclear processing directions and the group wanted to make sure they had guidance on processing the applications so they pulled them.”

When Sandy Levin (Mich.), the ranking Democrat on the panel, complained that no evidence of corruption or political influence has been found, Boustany replied, “I want to emphasize that this committee’s investigation is not complete.”

Perhaps he should have kept that in mind before accusing the administration of a crime.

Twitter: @Milbank

Read more from Dana Milbank’s archive, follow him on Twitter or subscribe to his updates on Facebook.