Obama's worst week so far: Why it matters

President Barack Obama pauses as he speaks on the Affordable Care Act in the Brady Press Briefing Room of the White House on November 14, 2013 in Washington.
Mandel Ngan | AFP | Getty Images

President Barack Obama just experienced his worst week in the White House with his personal and job approval ratings plummeting and his signature domestic achievement at serious risk of failure.

All is by no means lost for this president, who has experienced similar dips in the past, notably after the 2011 debt limit crisis. But the risks are much higher now because he is losing support among Democrats in Congress, imperiling any hopes for the rest of his domestic agenda.

The respected poll conducted by Quinnipiac College this week found that 54 percent of voters disapprove of Obama's job performance while just 39 percent approve, the president's worst rating ever.

According to Gallup, the number of Americans who view Obama as "honest and trustworthy" is down to just 50 percent from 60 percent during the 2012 re-election campaign. And only 47 percent now believe Obama is a "strong and decisive leader," the first time during his presidency that Obama has been below 50 percent on that question.

And if the health care law is not working well by next year, Republicans will stand a much greater chance of both holding the House and retaking the Senate by using Obamacare to bludgeon the many vulnerable Democrats running for re-election in GOP-leaning states.

Pres. Obama meeting with insurance executives

A second Quinnipiac survey found that Democrats have now completely lost the 9-point advantage they recently held over Republicans in a generic ballot House matchup. That means the Obamacare debacle vaporized gains Democrats made following the deeply unpopular government shutdown and debt ceiling crisis.

The effort by Republicans to run on Obamacare is already well underway with operatives constantly hammering vulnerable red state Democrats such as Mary Landrieu in Louisiana, Kay Hagan in North Carolina and Mark Pryor in Arkansas over their support for the Affordable Care Act.

Such attacks are why Landrieu and other Democrats are pushing for legislative changes to the law to allow people to keep existing plans that go beyond what the White House wants to do through its (probably unworkable) administrative fix.

(Read more: The Obamacare 'fix' is in: Now, where do we go from here?)

Obama and his party can recover from the current crisis. But there is only one way for that to happen: The health care law has to start working, and fast.

The president himself, in his apology-laden press conference on Thursday, acknowledged that his own future and that of his party rests on more people getting covered by the Affordable Care Act and liking the new coverage they get.

"I am confident that by—by the time we look back on this next year, that people are going to say this is working well, and it's helping a lot of people," Obama said.

(Read more: Obama: We fumbled the rollout of health-care law)

If that doesn't prove true, the president could spend the final two years of his presidency merely fighting off efforts of a GOP-controlled Congress to further cut spending, repeal the health care law, change the Dodd-Frank financial reform law and otherwise chisel away at accomplishments the president made in the first term.

If there is any silver lining to the current Obamacare brawl in Washington is that it probably further reduces the likelihood of more shutdowns and debt ceiling debacles. Republicans now have the president and the health care law on the ropes without using fiscal deadlines as threats.

And the more they gain political advantage the less they are going to want to squander it on risky strategies that tend to anger the public and damage the economy. From that perspective, investors should probably cheer the health care fight as a less damaging way for an entirely dysfunctional Washington to spend its time.

(Read more: Obamacare fix puts insurers in a tough spot)

By Ben White, POLITICO's chief economic correspondent and a CNBC contributor. White also authors the daily tip sheet POLITICO Morning Money [politico.com/morningmoney] Follow him onTwitter @morningmoneyben.