[3]: 3–5  After returning home he worked in real estate and automobile sales in Purcell, Oklahoma, then decided to pursue a career in the petroleum business.

[5] In the mid 1940s, he founded a lobbying organization for oil speculators, the Texas Independent Producers and Royalty Owners Association (TIPRO), of which he became the first president.

Senator to succeed the retiring W. Lee O'Daniel was won by Lyndon Johnson, who defeated the more conservative Coke Stevenson by less than 100 votes in a bitter runoff election that included allegations of fraud.

[5] Porter ran an aggressive campaign and attempted to cut into Democratic strength by appealing to conservative voters.

[13] His solicitation letter highlighted his closeness with U.S. House minority leader Joseph W. Martin Jr. and suggested that Texans affiliated with the petroleum industry should contribute generously, because with Martin's help Congress could pass an oil and natural gas deregulation bill sponsored by Congressman Oren Harris, which most Texans favored.

[13] Porter's letter made it appear that the money raised would be a quid pro quo, which generated nationwide controversy that prevented the bill's passage.

[13] In 1960, Democrat John F. Kennedy only narrowly won Texas, despite the presence of Lyndon Johnson on the ticket as his vice presidential running mate.

[15] Porter continued to support Republican candidates in the 1960s and 1970s, including George H. W. Bush's campaigns for the U.S. House and Senate.

[21] Grover lost to Democrat Dolph Briscoe by less than three percentage points (47.8% to 45%), a further indication that Porter's efforts to create a competitive Republican Party in Texas were succeeding.