After coming in a full 12 percentage points behind opponent David Dewhurst in the May primary election, preliminary results indicate Ted Cruz has won the runoff election in the race for U.S. Senate in Texas.

Early voting results only gave Cruz a narrow lead, but it was one that he never looked back on. Final vote counts have Cruz earning 56.8 percent. The rise in popularity of the Tea Party-backed candidate has been used to illustrate the growing influence of the Tea Party in national politics.

"Tonight is a victory for the grassroots," Cruz said in a speech prepared for his election night watch party. "This is how elections are supposed to be decided—by 'we the people.'"

Cruz will be facing Democrat and former state representative Paul Sadler in the November election. Sadler defeated his opponent Grady Yarbrough with 63.1 percent of the vote with reports in from all precincts.

Roughly 10.3 percent of registed voters in Texas voted in the runoff election, according to data from the Texas Secretary of State.

All election results at this point are unofficial.

Updated 8 p.m. CST

As early voting results continue to come in, Cruz has widened his lead to 52.3 percent. As of 8 p.m., 571 of 7,957 precincts have reported statewide.

Updated 7:15 p.m. CST

The first of the early voting results are in and Ted Cruz narrowly leads David Dewhurst with 51.5 percent of the vote, a total of 32,795 votes to Dewhurst's 30,837.

The two candidates, competing for the U.S. Senate seat being vacated by Kay Bailey Hutchison, have similar stances when it comes to most issues. They both aim to repeal the Affordable Care Act, work to secure national borders and cut back on government spending. They are both pro-life and have pledged to defend religious freedoms.

Throughout the campaign, Cruz has separated himself from Dewhurst by aligning with the Tea Party movement and casting himself as a grassroots politician. After receiving 34.2 percent of the vote in the May primary to Dewhurst's 44.6 percent, statewide polls have shown Cruz's popularity rising. A July 29 poll by Public Policy Polling showed Cruz leading with 52 percent to Dewhurst's 42 percent.

Democratic candidate Paul Sadler leads Grady Yarbrough with 64.1 percent of the vote, a total of 49,420 votes to Yarbrough's 27,647.

The U.S. Senate race is the most expensive non-presidential race in the country, with more than $45 million total spent by all candidates and more than $26 million by Dewhurst and Cruz alone, according to the Center for Responsive Politics.