Barely 10 months after exuberant Republicans took undivided control of government in Washington, their prevailing mood has turned to desperation.

Today former national security advisor Michael Flynn announced he is cooperating with special counsel Robert Mueller's investigation into potential collusion between President Trump's campaign and Russians who interfered in the 2016 election. That investigation puts the survival of the Trump presidency in danger.

At the same time, Senate GOP leaders are racing to pass their tax-cut bill even though their in-house experts told them it will spur little economic growth and add $1-trillion to the national debt. After initially exploring ideas to reduce the deficit impact, they abandoned them and moved to obtain the needed votes with concessions that increased it.

One prod for the frenzied rush: a looming special election in Alabama on Dec. 12. Losing it could shrink the Republican majority from 52 to 51 and imperil the tax bill's final passage.

The other: thwarted on health care, GOP lawmakers worry aloud that failure to cut taxes could choke off their campaign contributions and help Democrats win back Congress in mid-term elections. Ironically, Republican victory in that special election could help pass tax cuts but then damage the party in 2018 anyway. The Alabama Republican Senate nominee stands accused of sexually assaulting a child.

All that amid a swirl of reports – denied by Trump on social media this afternoon - of an impending administration shakeup that would dump Secretary of State Rex Tillerson, replace him with CIA Director Mike Pompeo, and replace Pompeo with Republican Sen. Tom Cotton of Arkansas. If that occurs, in less than a year the Trump team will have churned through its White House chief of staff, press secretary, communications director, top security aide and top diplomat, among others.

These are not simply inside-Washington problems. Public opinion has turned lopsidedly against the president and his party.

In today's Gallup tracking poll, just 34 percent approve of Trump's performance as president. He is the least popular first-year president in polling history.

In today's realclearpolitics.com average, Democrats hold a 9-percent lead over Republicans when Americans are asked which party they favor for Congress. Though Republicans feel intense pressure to pass a tax-cut plan, that may not help either. Polling has shown Americans oppose it by a two-to-one margin.

The specter of an administration consumed by scandal can only dig the Republican hole deeper. Mueller has previously indicted Mr. Trump's campaign chairman Paul Manafort and his deputy Rick Gates.

Campaign foreign policy advisor George Papadopoulos, like Flynn today, has already plead guilty to a crime in the Mueller investigation. The cooperation of both those men points toward peril for other key figures who have belatedly acknowledged contacts with Russians, including Attorney General Jeff Sessions, Trump son-in-law Jared Kushner, and Donald Trump Jr.

It also points toward peril for President Trump. His unbroken solicitousness toward Vladimir Putin, his public appeal to Russians to obtain Hillary Clinton's emails, and his firing of FBI Director James Comey amid the bureau's Russia investigation have raised questions for a long time.

But the fact that prosecutors have struck a cooperation agreement with Flynn signals that he has agreed to share information that may incriminate bigger targets. Officially, at least, the only bigger target than the national security adviser in the White House is the president.