Texas Republican Sen. Ted Cruz's 21-hour 'filibuster' on defunding Obamacare earlier this week has cemented his place as a viable 2016 candidate, as the first-term senator now leads in the Republican primary race according to a new Public Policy Polling study released Friday.

Cruz leads the pack with 20 percent of the vote, followed by Kentucky Sen. Rand Paul with 17 percent and New Jersey Gov. Chris Christie with 14 percent of the vote. Trailing behind them are former Florida Gov. Jeb Bush with 11 percent, and Florida Sen. Marco Rubio and Wisconsin Rep. Paul Ryan with 10 percent. Louisiana Gov. Bobby Jindal, former Pennsylvania Sen. Rick Santorum and Wisconsin Gov. Scott Walker all received less than five percent of the vote.

While the Lone State Republican's popularity rose by eight points since PPP's July study, everyone else in the field stayed relatively stagnant. Cruz is also outperforming his potential primary opponents among "very conservative" primary voters, pulling in one in three of them to Paul's 17 percent and Ryan's 12 percent. Christie remains in the lead among moderate voters, however, with 34 percent of the vote to Bush's 12 percent and Rubio's 10 percent.

Cruz's popularity soared in the wake of the 'filibuster', as he effectively made himself the face of the battle to defund Obamacare. According to the poll, 64 percent of Republican primary voters would rather see the federal government shut down at midnight on October 1, and nearly four times as many voters trust Cruz more than Senate Minority Leader Mitch McConnell (R-Ky.), 49 percent to 13 percent.

“Ted Cruz this week established himself as the grassroots hero of the Republican Party,” Dean Debnam, the president of Public Policy Polling, said in a statement to The Daily Caller. “The party base has a lot more faith in him than their more official leaders like Mitch McConnell and John Boehner.”

Public Policy Polling conducted a telephone survey of 743 Republican primary voters nationwide from September 25-26, 2013. The study has a margin of error of +/- 3 percentage points at a 95 percent confidence level.