Texas Sen. Ted Cruz has surpassed Donald Trump for the top spot in a new national survey of the Republican presidential race from NBC News/Wall Street Journal.

Cruz leads the poll with the support of 28 percent of those surveyed, followed by Trump at 26 percent, Florida Sen. Marco Rubio at 17 percent, Ohio Gov. John Kasich at 11 percent, and Ben Carson at 10 percent.

Trump dropped seven percentage points since last month, and hit his lowest point in the NBC/WSJ poll since October 2015 when Carson took the top spot. Cruz and Kasich each gained eight percentage points since January, the largest improvement of any candidate, and received their highest level of support ever in the poll.

"When you see a number this different, it means you might be right on top of a shift in the campaign," said Bill McInturff, who conducted the survey with a Democratic pollster on behalf of Hart Research Associates, to NBC. "What you don't know yet is if the change is going to take place or if it is a momentary 'pause' before the numbers snap back into place."

Former Florida Gov. Jeb Bush received the support of 4 percent of those surveyed, which falls within the poll's 4.9-percentage point margin of error for the GOP primary voters it surveyed. His support failed to equal half of the support received by any other Republican candidate still running for the nation's highest office.

The NBC/WSJ poll was conducted after Trump's victory in the New Hampshire primary and after the South Carolina GOP presidential debate aired by CBS. The poll surveyed 400 Republican primary voters from February 14-16.

The new poll places the escalating Trump-Cruz feud in perspective, as Trump's legal team formally served the Cruz campaign with a cease-and-desist letter on Wednesday pertaining to ads targeting Trump. Cruz's legal team responded and the senator held a fiery press conference goading Trump to follow through on his threats.

South Carolina Republicans will cast their ballots on Saturday and Nevadans will caucus for the GOP on Tuesday.