The victims of free-trade agreements are finally getting the attention they deserve, after 25 years of being minimized or outright ignored.

Maine, in particular, has been a ground-zero for free-trade-related economic casualties — more than 33,000 manufacturing jobs lost, a familiar casualty list of shoe, then shirt, then paper mill factories shuttered, entire communities economically depressed as a result.

The justifiable anger of those who have suffered is being stoked by a presidential candidate who suggests that he will be a one-man posse, round up those exported jobs like so many stolen head of cattle, and bring them back. But the damage is done, and these jobs won’t be coming back. Globalization trends in the past decades now prevent reversal of the damage that free-trade deals jump-started in the late 1990s.

What we should also know, in this election campaign of high heat, but less light, is how, first, the North American Free Trade Agreement then the Central America Free Trade Agreement happened, because, while there’s no magic cure for the damage they caused, things can get far worse if the Trans-Pacific Partnership is passed by Congress later this year.

Courtesy of the TPP, America is at risk, not only for more job loss and business closures, its provisions also permit foreign companies to sue the U.S. government for enforcing national, state and even local laws if those laws interfere with their profits. Don’t assume that this free-trade agreement is already dead. Far from it.

So here’s a quick legislative history lesson that might surprise, if all we listen to is presidential candidates trolling for votes:

NAFTA was negotiated and signed in 1992 by — wait for it — President George H.W. Bush, not Bill Clinton. President Clinton signed the enabling law the following year and, indeed, supported it. But the law was passed in both houses by a majority of Republicans and and only a minority of Democrats.

Thirteen years later, CAFTA was negotiated by President George W. Bush, who signed it into law in July 2005. That law was narrowly passed, with an even larger majority of Republican and even smaller minority of Democratic legislators in both houses of Congress.

The TPP has been negotiated under the auspices of President Barack Obama, an enthusiastic free trader. He is intent on getting this most wide-ranging of all free trade agreements passed before he leaves office. Hillary Clinton and Donald Trump both oppose it. Lopsidedly, Democratic legislators are opposed; Republicans largely in favor, including the Republican leadership.

If the TPP passes, it will be passed almost exclusively by Republicans in both House and Senate, with a few wayward Democrats lending support.

So, a message to anyone who cares about Maine not incurring yet more pain from free-trade agreements that cost jobs and close more factories, and a caution to those who don’t want to enable trans-national companies to supersede U.S. laws ensuring fair labor practices, public health and safety and environmental protections:

Presidents sign laws, but it is Congress that passes them. NAFTA and CAFTA were passed, could only have passed, with significant Republican majorities. The Trans-Pacific Partnership will only pass with heavy Republican support.

Donald Trump’s opposition to the TPP is not a typical Republican party position. Despite election rhetoric, Congressional representatives are rarely profiles in political independence once they are back in office. They will be under intense pressure to vote according to party-line dictates.

Historically, representatives vote their party’s line well over 90 percent of the time. This trend is getting only more extreme in the highly polarized political environment.

Once bitten, twice shy, they say. With NAFTA and CAFTA, Mainers have already been twice bitten. Now imagine this predictable scenario: A President Hillary Clinton opposes the TPP. An aggrieved opposition party vows to oppose her at every turn. That party’s leadership demands that its members be in lockstep or risk reprisal.

No matter what campaign promises anyone is making, Mainers should swallow hard before betting their economic welfare on Republican legislators bucking their party in the political climate that looms ahead.

Dennis Chinoy works with Power in Community Alliances in Bangor, which focuses on the impact of free-trade agreements on Maine.