Canada's most important new trade agreement has turned into a political football in Washington's all-consuming impeachment clash.

Republicans and Democrats have both seized upon the not-yet-ratified Canada-U.S.-Mexico Agreement (CUSMA) on trade to try to win the argument over who's properly conducting the nation's business amid the impeachment fight.

Hanging in the balance of this partisan scrum: A new trade agreement that would govern more than three-quarters of all Canada's exports.

To Republicans, the continuing failure to ratify CUSMA is evidence their opponents are do-nothing, president-tormenting partisans who deserve to lose their House majority in next year's election.

"What's going on is a disgrace," President Donald Trump said Tuesday of the impeachment hearings.

"It's an embarrassment to our nation. And in the meantime we can't get [CUSMA] approved because [House Speaker] Nancy Pelosi is grossly incompetent."

Watch U.S. President Donald Trump assess what's holding up the new NAFTA.

The Canada-U.S.-Mexico Agreement on trade is being pulled into the ongoing impeachment proceedings south of the border. 1:12

At the same time, Republicans are using the moment to push for the Democratic-controlled House of Representatives to approve the deal, which Americans refer to as the United States-Mexico-Canada Agreement​, or USMCA.

Approval in that chamber would pave the way for the agreement's enactment in all three countries, replacing the North American Free Trade Agreement (NAFTA).

Democrats have been talking to the administration about adjustments to the pact that would satisfy their critical allies in the labour movement — but there's no deal yet.

Administration officials blanketed the airwaves with their messaging Tuesday. Trump, Vice-President Mike Pence and cabinet officials conducted 17 local radio and TV interviews to push the NAFTA 2.0 message to millions of American households.

House Speaker Nancy Pelosi says Democrats are working to make necessary adjustments to the trade deal so it can be passed. Trump says she's responsible for holding up the process. (Susan Walsh/The Associated Press)

At the impeachment hearings, the trade deal keeps coming up — Republicans frequently mention it as Exhibit A of what Congress should really be working on.

And at a White House event on drug costs last week, Trump said: "Canada keeps calling me: 'When is this deal going to happen? Is this deal going to happen?'"

White House official Marc Short told reporters Tuesday that despite recent claims from Democrats that they're close to a deal on ratification, there's been little progress — on it, or anything else, in this Congress.

"Can any of you name any substantive legislation [Democrats] have passed that's come to the president's desk? There's not a thing," Short said.

He noted that Democrats won their House of Representatives majority thanks to gains in nearly three-dozen districts that also voted for Trump.

Now these swing-district Democrats are urging their party leadership to pass the deal — so they have a bipartisan accomplishment they can show voters back home.

Democrats must 'show that they can govern'

Some supporters of the agreement remain optimistic it will be adopted.

The head of one prominent business group predicted weeks ago, immediately after hearing Pelosi announce the impeachment investigation, that this would, perhaps counter-intuitively, make it more likely that CUSMA will be adopted.

She's sticking with that prediction.

"House Democrats need to be able to show that they can govern," said Maryscott Greenwood, head of the Canadian American Business Council.

"They need to be able to prove to voters that giving them a majority matters, and that they will use their majority wisely. This means they need to be able to legislate while they litigate."

Democrats argue that's exactly what they're doing.

In an off-camera exchange with journalists Tuesday, a senior Democrat, House Majority Leader Steny Hoyer, ticked through a list of real and potential accomplishments in this congressional session.

House Majority Leader Steny Hoyer, seen here on Capitol Hill in October, told reporters his fellow Democrats are still getting legislative work done despite the impeachment proceedings. (Jose Luis Magana/The Associated Press)

Some items were routine: Hoyer's list of potential bills in the works include spending measures to avoid a government shutdown, as well as annual funding for the Pentagon.

Other items stand little chance of passing the Republican Senate, including a clean-government reform package, a wide-ranging ethics bill that introduces scores of changes to the political process, such as new disclosure rules for campaign contributions, new controls prohibiting foreign donations and helping states create non-partisan redistricting bodies. It was the Democrats' first priority in this Congress but has gathered dust in the Senate.

Hoyer's list did include one notable example of a potentially significant new law, which both parties could conceivably agree on in this Congress.

It was the Canada-U.S.-Mexico Agreement.

Hoyer said lots of work has been done to strengthen the agreement's labour provisions. He said his party wants to get to "yes" on the pact, and get it passed sooner rather than later.

He finished the exchange with reporters in his office by returning to his central point: that Democrats are getting things done.

"So I hope all of you would convey to the American people, when the Republicans say we are dissuaded by impeachment, that that is not accurate," Hoyer said.

Primary season looming

Supporters of the trade pact hope to see it ratified before the holidays.

However, one Canada-U.S. trade lawyer said he sees the harder deadline being around Feb. 3. That's the date of the Iowa Democratic caucuses.

Dan Ujczo, of the firm Dickinson Wright, said it will become harder for Pelosi's team to push the trade deal forward later in the winter, if her party's presidential candidates start bashing it during primary season.

Sen. Bernie Sanders, left, former vice-president Joe Biden, centre, and Sen. Elizabeth Warren are seen on stage during a debate in Westerville, Ohio, last month. Passing the new NAFTA could become more complicated if it faces increased criticism from contenders seeking the Democratic presidential nomination. (Win McNamee/Getty Images)

Democratic presidential candidates have systematically opposed new trade deals in recent campaigns, and several progressive candidates in this cycle have already come out against the new NAFTA. While Democratic voters tell pollsters they like free trade, the unions that provide valuable organizational strength during campaigns do not usually support trade deals.

Democrats have closely consulted with the American Federation of Labor and Congress of Industrial Organizations (AFL-CIO) throughout this process, and gauged its support for the deal; after a meeting on Capitol Hill with leader Richard Trumka on Tuesday, it was clear that the country's largest labour federation is still not onside.

If Democratic presidential hopefuls get vocal in their opposition to CUSMA, "You're going to have some terrible optics," Ujczo said.

"To me that's the real clock — the presidential campaign."