[6] Flores served as the chief financial officer (CFO) for two publicly traded energy service firms from 1990 through 1998: Marine Drilling Companies, Inc. (1990–1997) and Western Atlas Inc. (1997–1998).

[9] In 2006, a group of five oil and gas industry executives, led by Flores as president and CEO, formed Phoenix Exploration Company with $350 million of capital commitments from a group of private equity firms that included Riverstone Holdings and Pinebrook Partners.

[10] Flores also served as a director of that company from its formation until he retired in December 2009 to run for public office.

[6] In late 2009 Flores entered the Republican primary for the 17th District, held by 10-term Democratic incumbent Chet Edwards.

[16] The size of his primary victory was a surprise to many political observers because Curnock was the 2008 nominee and he held Edwards' 2008 vote total close to 50 percent, despite being heavily outspent.

Senator Phil Gramm[18] After the primary win, Flores was also endorsed by George H. W. Bush, John McCain,[19] Mitt Romney, and Mike Huckabee.

[citation needed] Flores won his fourth term in the U.S. House in the general election held on November 8, 2016.

Flores supported President Donald Trump's 2017 executive order to temporarily curtail Muslim immigration until better screening methods are devised.

"[28] In December 2020, Flores was one of 126 Republican members of the House of Representatives who signed an amicus brief in support of Texas v. Pennsylvania, a lawsuit filed at the United States Supreme Court contesting the results of the 2020 presidential election, in which Joe Biden prevailed[29] over incumbent Donald Trump.

The Supreme Court declined to hear the case on the basis that Texas lacked standing under Article III of the Constitution to challenge the results of the election held by another state.

Flores was elected on the second ballot, securing 84 votes to South Carolina Representative Mick Mulvaney's 57.