The defeat of Congresswoman Renee Ellmers in her North Carolina primary should serve as a warning to those Republicans who think that, once elected, they can ignore their conservative constituents.

Ellmers was elected in 2010 with Tea Party support and the endorsement of Sarah Palin. As a former nurse, her strong criticism of ObamaCare carried extra credibility.

On Tuesday night, Ellmers not only lost but was in danger of dropping to third in her primary as the last few votes trickled in. Her decision to abandon constitutional conservatism and follow Washington’s “business as usual” course persuaded her constituents that it was time for a change.

Perhaps Ellmers’ biggest mistake was voting to reauthorize the Export-Import Bank after the House had successfully killed it in 2015. The Bank is one of the most blatant forms of corporate welfare, providing subsidies to big companies such as Boeing and Intel. Its defeat was touted as one of the few cases in which the GOP Congress successfully defied President Obama. However, a furious lobbying campaign by Big Business succeeded in getting the House to reverse itself and keep the subsidies flowing.

Ellmers campaigned by boasting about her work with liberal Democrats, including Democratic National Committee Chairman Debbie Wasserman-Schultz. She voted in favor of a “bipartisan” spending bill that funded programs favored by President Obama.

The voters were not impressed. They were looking for a conservative, and chose to support Rep. George Holding, who ended up running in Ellmers’ district when a Federal judge redrew the district lines.

The lesson should be clear. Conservative voters expect their elected officials to keep their promises. Those who don’t should expect to be sent home.

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