On Tuesday, 75 Republicans pressured by our leadership and a weak-kneed Senate joined 182 Democrats in abandoning a provision blocking President Obama’s executive actions on immigration in the Fiscal 2015 Department of Homeland Security spending bill. Without a doubt, Congress ceded its constitutional authority when it gave up the fight to ensure the president faithfully executes the laws of the United States.

Unfortunately, the outcome was predictable. In December, I cautioned the Republican Conference that separating the Department of Homeland Security from the rest of the budget was a losing strategy. It is with some amusement that I read in the press that the Republicans who voted with leadership and the Democrats to fund Homeland Security are the grownups in the room. These same Republicans voted with leadership back in December for the funding bill that led to this disastrous outcome.

These so-called “adults” ignored my warnings and those of many of the most conservative members of the House that we could never win a fight that put Department of Homeland Security funding in jeopardy. We suggested in December that Congress pass a two-month funding bill to give House and Senate Republicans time to come up with a winning strategy.

Nonetheless, even when we didn’t agree with the strategy, House conservatives continued to fight to undo the president’s illegal and unconstitutional executive amnesty. But we lost because the Democrats and the White House outsmarted ineffective GOP leadership.

This fight is not about differences over immigration policy, it’s about protecting the constitutional prerogative of Congress to make law.

Not only did our leaders rely on Democratic votes, they caved to Senate Democrats who refused to let the issue be debated. They rebuffed proposals from the newly formed House Freedom Caucus — of which I am a founding member — to temporarily extend the Department of Homeland Security spending bill so the constitutional process of negotiations between the House and Senate could resolve our differences.

In the end, I was among 167 Republicans who voted against leadership’s capitulation. I did so because I took an oath to uphold the Constitution of the United States.

Our great country was founded on the principle that we need a government strong enough to protect our God-given rights but not so powerful as to encroach on individual liberties. At the heart of the genius of the Constitution are the checks and balances inherent in our three branches of government.

Article I, Section 1 is not open to interpretation: “All legislative Powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives.”

Presidents are charged with executing the law, not making it. Yet President Obama’s executive actions put 5 million people who came to the U.S. illegally ahead of those who play by the rules – a unilateral usurpation of congressional power.

Make no mistake; this fight is not about differences over immigration policy, it’s about protecting the constitutional prerogative of Congress to make law. Instead of standing up for the separation of powers and the rule of law, the House voted to cede its constitutional authority.

I fear this loss of nerve will embolden this president and future presidents of both parties to use executive action when they can’t get what they want from Congress.

Can’t persuade Congress to enact more environmental restrictions? Issue an executive order. Don’t like the capital gains tax? Quit collecting it. Sooner or later, every member of Congress, regardless of ideology or party, will live to regret this Congress’ failure to stop President Obama’s executive actions.

Despite this grave setback, the battle is not over. I promise to continue fighting for you.