Senator John Cornyn (R-Texas) will not be endorsing Senator Ted Cruz (R-Texas) in the Republican Presidential Primary. As Breitbart Texas reported, Cruz officially became 2016’s first Republican presidential candidate this week with a Tweet posted shortly after midnight Monday morning, followed by an announcement speech delivered at Liberty University in Lynchburg, Virginia.

Cornyn, the Senate Majority Whip, was asked about his fellow Texas Senator’s candidacy in an interview with Politico on Monday, just a few hours after Cruz’s speech. Cornyn cited the crowded primary field as his reason for staying neutral.

“You know, we’ve got a lot of Texans who are running for president, so I’m going to watch from the sidelines,” said Cornyn. In addition to Cruz, former Governor Rick Perry (R-Texas) is expected to throw his hat in the ring, and several other potential candidates have ties to Texas as well.

Senator Rand Paul (R-Kentucky) grew up in Lake Jackson, attended Baylor University, and his father, former Congressman Ron Paul (R-Texas), represented a district in the Greater Houston area. Former Governor Jeb Bush (R-Florida) was born in Midland, grew up in Houston, and graduated from the University of Texas at Austin. The Texas Tribune ran an article in January noting several other potential candidates who have connections to the Lone Star State, including former Hewlett-Packard CEO Carly Fiorina, who was born in Austin, and former Senator Rick Santorum (R-Pennsylvania), whose family-friendly film company is based in Flower Mound.

Cornyn told Politico that his refusal to endorse Cruz for President was not retribution for Cruz’s decision to stay neutral in Cornyn’s Senate race last year. Cornyn easily dispatched a crowded field of challengers to win the 2014 Republican nomination. Once the primary was over, however, Cruz did endorse Cornyn in the general.

Cornyn was also asked if he would donate to Cruz. “Nope,” said Cornyn. “You got a lot of people involved, and I don’t see any benefit to them or to me.”

Texas’ two Senators have a friendly personal relationship but have clashed several times over policy and strategy disagreements. They split their votes on President Barack Obama’s nomination of former San Antonio Mayor Julian Castro as Secretary of Housing and Urban Development, with Cornyn voting for Castro’s nomination and Cruz voting against. They have also publicly disagreed about what the Republican Senators’ strategy should be regarding Obama’s Attorney General nominee, Loretta Lynch, although both do oppose her nomination, as Breitbart Texas reported.

Cruz and Cornyn also traded barbs over the October 2013 government shutdown in a pair of speeches delivered at The Texas Tribune Festival last September. Cruz’s role in the shutdown was viewed as a risky, divisive move by many of his Senate Republican colleagues, who pointed out the difficulty of achieving any political victories while the Democrats still controlled the Senate, but on the other hand was cheered by many of the same grassroots conservatives who are likely to be a part of his base of support for his presidential run.

Follow Sarah Rumpf on Twitter @rumpfshaker.