They might demand a bigger budget, but that still needs to be approved by congress.
This snipet from Chris Murphy addressing Noem at the U.S. Senate Appropriations Subcommittee on Homeland Security in May reveals either her lack of knowledge and/or disregard for the laws she's supposed to uphold:
“You're on track to trigger the Anti-Deficiency Act. That means you are going to spend more money than you have been allocated by Congress. This is a rare occurrence, and it is wildly illegal. Your agency will be broke by July, over two months before the end of the fiscal year. You may not think that Congress has provided enough money to ICE, but the Constitution and the federal law doesn’t allow you to spend more money than you've been given, or to invent money. And this obsession with spending at the border, as the Chairwoman mentioned, has left the country unprotected elsewhere. The security threats to the United States are higher, not lower, than before Trump came to office. To fund the border, you have illegally gutted spending for cybersecurity. As we speak, Russian and Chinese hackers are having a field day attacking our nation. You have withdrawn funds for disaster prevention. Storms are going to kill more people in this country because of your illegal withholding of these funds. Your myopia about the border, fueled by President Trump's prejudice against people who speak a different language, has shattered many of this country's most important defenses.