The latest poll ahead of the South Carolina primary finds Donald Trump with a commanding 19 point lead over his nearest rival, Texas Sen. Ted Cruz. The survey, of likely Republican primary voters, shows Trump with 34 percent of the vote, followed by Cruz with 15 percent.

Jeb Bush leads Marco Rubio for third place. Bush edges Rubio 13 to 12 percent. Ohio Gov. John Kasich is a distant fourth with 8 percent support. Neurosurgeon Ben Carson is last, with 5 percent.

Trump leads the GOP field among every age group. His biggest margins, however, are among seniors and voters older than 55. In 2012, these voters made up over 60 percent of the primary electorate.

Trump’s smallest margin is among voters 18-25. With these voters, Trump leads Cruz by just 6 points, 28-22 percent. Jeb Bush is a very distant third with 11 percent. No other candidate receives double-digit support from young voters. These voters, however, made up just 9 percent of the vote in 2012.

Trump also enjoys a wide lead across all parts of the ideological spectrum. Trump leads Cruz by 15 points among “conservative Republicans,” 35-20. Among “moderate Republicans”, who make up about a quarter of the electorate, Trump has 31 percent, while Rubio has 20, Bush 19 and Kasich 18 percent support.

Trump has a massive lead among “libertarian” Republicans, gaining 59 percent support against 17 percent for Cruz. Libertarians, however, make up a small fraction of the overall primary electorate. Still, it shows that Trump draws significant support from all parts of the Republican tent.

Only among self-identified “tea party Republicans” does the Trump wave hit some rocks. He and Ted Cruz effectively split their votes, with Trump getting 37 percent against Cruz’s 36 percent. Marco Rubio is very far back with just 9 percent support among these voters.

The poll was conducted by the South Carolina House Republican caucus and interviewed just over 1,200 likely primary voters on Thursday and Friday.

The poll provides a good baseline to analyze any impact from Saturday’s GOP debate in Charleston. With only 6 candidates on stage, the debate is likely to feature aggressive interaction among the candidates.

Conventional wisdom currently holds that Trump and Cruz are battling each other for a victory in the primary next Saturday, while Bush, Rubio and Kasich are fighting for third place. This poll certainly confirms that status of the race before the debate.

Trump currently has a great deal of momentum in the Palmetto State following his landslide victory in New Hampshire on Tuesday. With a debate and a week of campaigning, though, the race can turn quickly.

Trump’s momentum may be difficult to stop, however. How the other candidates finish in the primary will have a dramatic impact on the remainder of the primary contest.

Marco Rubio faces the toughest task, having dropped in the polls since his performance in the last GOP debate just a week ago. Bush edged him in New Hampshire and, right now, looks set to edge him again in South Carolina. Another finish behind Bush would make it difficult for Rubio to consolidate the mainstream Republican vote behind him.

Cruz is also in a difficult spot. After winning the Iowa caucus, he faded to the background of the race as the other candidates launched aggressive campaigns in New Hampshire. Since then, Trump has improved his standing with conservative and evangelical voters. Unless Cruz can blunt this, he will be the perpetual runner-up in a hosts of contests set to unfold over the next several weeks.