Right now, in Mission, Tex., we don’t worry about immigrants who crossed the border illegally or drug smugglers. We worry about having to defend our private property from seizure by the federal government.

I work at the National Butterfly Center — which is along the U.S.-Mexico border — documenting wildlife and leading educational tours. Many of our visitors are young students from the Rio Grande Valley. When they first arrive, some of the children are scared of everything, from the snakes to the pill bugs. Here, we can show them animals that roam free and teach them not to be afraid. We talk about how we planted native vines, shrubs and trees to attract some 240 species of butterflies, as well as dragonflies, grasshoppers and other insects. The bugs brought the birds — including some you can’t see anywhere else in America, like Green Jays and Chachalacas — and from there, the bobcats and coyotes. We want to teach kids what it takes to create a home for all kinds of animals.

President Trump’s new border wall — which he has threatened to shut down the government to fund — will teach them what it takes to destroy it.

The first section, funded by Congress in 2018 for construction starting early next year, will cut right through our 100-acre refuge, sealing off 70 acres bordering the banks of the Rio Grande. The plan that we’ve seen calls for 18 feet of concrete and 18 feet of steel bollards, with a 150-foot paved enforcement zone for cameras, sensors, lighting and Border Patrol traffic. On the south side of the barrier, flooding will worsen. On the north side, animals (including threatened species like the Texas tortoise and the Texas horned lizard) will be cut off from ranging beyond the wall for feeding and breeding. Flood lighting will disrupt the usual patterns of nocturnal species. We dread the destruction that will come when the bulldozers arrive, which could be as early as February. That loud, heavy machinery will cause irreparable damage to the habitat we’ve worked so hard to restore.

We’re not the only ones standing in the wall’s path. It will also slice through the Santa Ana National Wildlife Refuge, and in Bentsen-Rio Grande Valley State Park — which draws birdwatchers from all over the country and has hosted countless picnics and barbecues for local families like mine. The wall will cut through the park’s land that is behind its parking lot and visitor center. There isn’t much public open space in the Rio Grande Valley. What’s there is fragmented and precious to all of us: According to a 2011 estimate, ecotourism brings $463 million a year to our economy and supports more than 6,600 jobs.

I’m a lifelong Republican who voted for Donald Trump for president in 2016. I want our immigration laws to be enforced, and I don’t want open borders. But Mission is not a dangerous place. I’ve lived here all my life. Here at the National Butterfly Center, 6,000 schoolchildren visit each year. Girl Scouts come here when they camp overnight just a mile or so from the Rio Grande. When the president says there’s a crisis at the border that requires an action as drastic as building a massive concrete wall, he either knows that it’s not true or he’s living in an alternate reality.

Five myths about the U.S.-Mexico border

Before this controversy, I voted, and sometimes I expressed my political views on Facebook, but this issue got me involved in activism for the first time. I had never gone to a protest in my entire life, but last year, I helped organize one: a four-mile march to the La Lomita Chapel, a historic church on U.S. soil that the wall will block. I also joined a group that succeeded in lobbying the Mission City Council to pass an anti-wall resolution. This is a mostly Democratic area, so these experiences were a little uncomfortable for me. Most of the people I worked alongside were anti-Trump from the start. I mostly kept quiet about my party affiliation and my vote in 2016.

People have asked me, “Didn’t you listen to Trump when he said that he would build a wall?” I didn’t take the idea seriously during the campaign. I knew he couldn’t get Mexico to pay it — that’d be like asking Hurricane Harvey to foot the bill for rebuilding Houston — and thought it was just talk: another candidate making big promises he couldn’t keep. I never thought it would actually happen.

By backing the wall, my party has abandoned the conservative principles I treasure: less government, less spending, and respect for the law and private property. The wall is expected to cost between $8 billion and $67 billion to build, and its rushed construction requires the waiver of 28 federal laws meant to protect clean air and water, wildlife habitat and historical artifacts. As I followed the news [last week], I was amazed to find myself agreeing with Rep. Nancy Pelosi (D-Calif.), who called the project “immoral, ineffective and expensive.” Here was a Democrat telling a Republican that a policy would cost too much.

For now, it looks like construction will plow ahead. Even before Congress appropriated funding, government contractors illegally entered our property and started cutting down trees and clearing brush without permission or notice. [Recently,] I caught land surveyors on camera who had hopped our fence to mark off property lines. A second set of surveyors arrived a few days later, accompanied by armed federal agents to guard them from visitors who might approach with questions.

Still, I want to be able to tell my grandchildren and great-grandchildren that I fought against the wall. I worry that, if it goes up, their only experience of the Rio Grande Valley’s natural beauty will be through the photographs that I take today.

If Donald Trump runs for a second term, he will not get my vote.

As told to Washington Post editor Sophia Nguyen.