Answer by taking a quote from the following article:

Rafael Edward Cruz (; born December 22, 1970) is an American politician and attorney serving as the junior United States Senator from Texas since 2013. He was a candidate for the Republican nomination for President of the United States in the 2016 election. Cruz was raised in Houston, Texas. After high school, he attended and graduated from Princeton University and Harvard Law School.

Cruz's victory in the Republican primary was described by the Washington Post as "the biggest upset of 2012 ... a true grassroots victory against very long odds". On January 19, 2011, after U.S. Senator Kay Bailey Hutchison said she would not seek re-election, Cruz announced his candidacy via a blogger conference call. In the Republican senatorial primary, Cruz ran against sitting Lieutenant Governor David Dewhurst. Cruz was endorsed first by former Alaska Governor Sarah Palin and then by the Club for Growth, a fiscally conservative political action committee; Erick Erickson, former editor of prominent conservative blog RedState; the FreedomWorks for America super PAC; nationally syndicated radio host Mark Levin; Tea Party Express; Young Conservatives of Texas; and U.S. Senators Tom Coburn, Jim DeMint, Mike Lee, Rand Paul and Pat Toomey. He was also endorsed by former Texas Congressman Ron Paul, George P. Bush, and former U.S. senator from Pennsylvania Rick Santorum. Former Attorney General Edwin Meese served as national chairman of Cruz's campaign.  Cruz won the runoff for the Republican nomination with a 14-point margin over Dewhurst. Cruz defeated Dewhurst despite being outspent by Dewhurst who held a statewide elected office. Dewhurst spent $19 million and Cruz spent only $7 million. Dewhurst raised over $30 million and outspent Cruz at a ratio of nearly 3-to-1.  In the November 6 general election, Cruz faced Democratic candidate Paul Sadler, an attorney and a former state representative from Henderson, in east Texas. Cruz won with 4.5 million votes (56.4%) to Sadler's 3.2 million (40.6%). Two minor candidates garnered the remaining 3% of the vote. According to a poll by Cruz's pollster Wilson Perkins Allen Opinion Research, Cruz received 40% of the Hispanic vote, vs. 60% for Sadler, outperforming Republican Presidential candidate Mitt Romney with the Hispanic vote in Texas.  After Time magazine reported on a potential violation of ethics rules by failing to publicly disclose his financial relationship with Caribbean Equity Partners Investment Holdings during the 2012 campaign, Cruz called his failure to disclose these connections an inadvertent omission.  In January 2016, The New York Times reported that Cruz and his wife had taken out low-interest loans from Goldman Sachs (where she worked) and Citibank, and failed to report the nearly $1 million in loans on Federal Election Commission disclosure statements as required by law. Cruz disclosed the loans on his Senate financial disclosure forms in July 2012, but not on the Federal Election Commission form. There is no indication that Cruz's wife had any role in providing any of the loans, or that the banks did anything wrong. The loans were largely repaid by later campaign fundraising. A spokesperson for Cruz said his failure to report the loans to the FEC was "inadvertent" and said he would be filing supplementary paperwork.

What happened after that?
Cruz defeated Dewhurst despite being outspent by Dewhurst who held a statewide elected office.