Washington (CNN) President Donald Trump has just one month left to salvage a lost legislative year in a presidency that he vowed would be an endless victory lap -- but has yet to produce a major new law that reshapes the nation.

The President's road to a congressional win could be paved by passing the first sweeping tax reform package in decades , which would appease restive Republican voters and represent an undeniable personal political triumph.

But it also comes strewn with obstacles, many of his own making.

Trump's tenuous relationship with his own party, and the split between the GOP's populist and establishment wings, will complicate the effort by Republican leaders to deliver on their monopoly on Washington power.

Democrats have the chance to leverage the threat of a government shutdown to advance their own agenda after stunning Republicans by tempting the President into a deal to avoid a previous fiscal crunch in September.

And controversy pitting Trump against GOP leaders over Roy Moore in the Alabama Senate race, and the darkening cloud of the Russia investigation, risk scrambling the President's concentration in the crucial weeks to come.

Trump's presidency has also often produced Washington storms that distract the White House from the events on which he will be judged by posterity.

By Monday, the administration was locked in a new legal tussle over executive power with the outgoing head of the Consumer Financial Protection Bureau Richard Cordray, who quit on Friday and named his former chief of staff Leandra English, as his interim successor.

The administration insists that the President has the authority to appoint an interim director, and Trump named his budget chief Mick Mulvaney, a longtime critic of the bureau, to the post.

The President, meanwhile, opened the week touting optimism over the possibility for a victory on Capitol Hill.

Back in D.C., big week for Tax Cuts and many other things of great importance to our Country. Senate Republicans will hopefully come through for all of us. The Tax Cut Bill is getting better and better. The end result will be great for ALL! — Donald J. Trump (@realDonaldTrump) November 27, 2017

"Back in D.C., big week for Tax Cuts and many other things of great importance to our Country," Trump tweeted Sunday night. "Senate Republicans will hopefully come through for all of us. The Tax Cut Bill is getting better and better. The end result will be great for ALL!"

But his frustration about his barren legislative record is revealed by another of his periodic attempts to rewrite political reality.

Since the first day I took office, all you hear is the phony Democrat excuse for losing the election, Russia, Russia,Russia. Despite this I have the economy booming and have possibly done more than any 10 month President. MAKE AMERICA GREAT AGAIN! — Donald J. Trump (@realDonaldTrump) November 26, 2017

"Since the first day I took office, all you hear is the phony Democrat excuse for losing the election, Russia, Russia,Russia," Trump tweeted earlier Sunday evening. "Despite this I have the economy booming and have possibly done more than any 10 month President. MAKE AMERICA GREAT AGAIN!"

Trump also tweeted a link at the weekend to a website listing his achievements in office, writing "Wow, even I didn't realize we did so much. Wish the Fake News would report! Thank you."

Wow, even I didn't realize we did so much. Wish the Fake News would report! Thank you. https://t.co/ApVbu2b0Jd — Donald J. Trump (@realDonaldTrump) November 25, 2017

The list largely reflected strong job growth, executive orders he signed on issues like immigration and minor bills passed by Congress.

But Trump has failed to use the moment of his maximum power to forge a legislative legacy, and his low approval ratings have dented his influence in Washington at a moment when most presidents achieve their biggest wins.

2018 looms

His hopes of a more prolific year in 2018 rest on lawmakers already fixated with midterm elections who will be wary of tough political votes.

Republican senators openly admit that their supporters could deal them a rebuke in November if they fail to produce tangible results for their lease on power by passing the tax reform bill.

"For every Republican senator, the fate of the party is in our hands, as well as that of the economy," Sen. Lindsey Graham, R-South Carolina, told CNN's Dana Bash Sunday on "State of the Union."

"The economy needs a tax cut, and the Republican Party needs to deliver. So, I think we will get there," he said.

The House has already passed its version of the tax reform bill. But the GOP's two-vote majority in the Senate leaves the fate of the legislation in the balance amid wrangling on the scope of the tax cuts, their likely swelling of the deficit and an effort to include a repeal of Obamacare's coverage mandate.

Outspoken Republican Trump opponents, such as Arizona Sen. Jeff Flake and Tennessee Sen. Bob Corker, must decide whether to hand a victory that could strengthen a President they have argued is barely fit for office.

Trump will head to Capitol Hill on Tuesday to rally Senate Republicans ahead of a possible vote on the tax reform this week.

In the long term, the tax reform package holds risk for Trump and his party.

Democrats are branding the package as a massive giveaway to the rich, highlighting its deficit implications and questioning the GOP promise that a huge corporate tax cut will ignite growth, raise wages and create jobs.

"There's a real problem, a trillion-and-a-half dollars added to the deficit, threatening Medicare and Social Security, tax breaks for the wealthiest people in America and the biggest corporations," Illinois Democratic Sen. Dick Durbin said on "State of the Union."

Durbin said that while tax breaks for the middle class will sunset, "the tax cuts for wealthiest people are permanent. That's just unfair, and that's why half of the American people are skeptical about this Trump tax plan."

Democrats must decide whether to make government funding conditional on their priorities -- including the renewal of a children's health care program and a rescue of undocumented migrants brought to the US as children, who are facing deportation.

Disagreement between the parties on those issues could spark a period of political brinkmanship and a government shutdown before Christmas.

The tax and government funding showdowns could also be colored by the question of whether Democratic gains in this November's elections are a dark omen for Republicans heading into midterm polls.

Cascade of sexual harassment allegations

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Washington is now also consumed by the cascade of sexual harassment allegations that are causing embarrassment for Democrats as well as the GOP.

Minnesota Democratic Sen. Al Franken said Sunday he would return to work "embarrassed and ashamed" over accusations he inappropriately touched several women. House Democratic Leader Nancy Pelosi is under fire for her handling of allegations against party icon Rep. John Conyers, who stepped down as the top Democrat on the House Judiciary Committee on Sunday.

The Roy Moore saga is twisting the Republican Party in knots ahead of the Alabama Senate election on December 12.

Trump effectively endorsed Moore before Thanksgiving, siding with his populist base against establishment GOP leaders, after several women accused Moore of pursing sexual relationships with them when they were in their teens and he was in his 30s.

One woman alleges Moore touched her inappropriately when she was 14. Another woman has accused Moore of sexually assaulting her when she was 16. The legal age of consent in Alabama is 16.

Moore has repeatedly denied the allegations.

Trump's lifeline to Moore has left the GOP with a lose-lose situation.

"If he wins, we get the baggage of him winning, and it becomes a story every day about whether or not you believe the women or Roy Moore, should he stay in the Senate, should he be expelled?" Graham said.

"If you lose, you give the Senate seat to a Democrat at a time where we need all the votes we can get," he said.

The widening scope of the Russia investigation will also further strain nerves in the White House in December. Reports that lawyers for former national security adviser Michael Flynn have cut off contacts with the President's attorneys have sparked speculation he is negotiating a deal to cooperate with special counsel Robert Mueller.

Such an agreement could indicate that Mueller's team has higher prey in mind in the investigation -- extending even further into the top ranks of the White House.

"It depends on what the President has done and what the President's conversations with Michael Flynn and others have been," said former US Attorney Preet Bharara, who is now a CNN contributor. "But if you have done bad things, then you should be very worried."