DALLAS (CBSDFW.COM) – Political experts say the race to succeed North Texas Congressman John Ratcliffe could become very crowded and attract multiple candidates.

On Sunday, President Donald Trump announced on Twitter that he will nominate the Republican lawmaker to succeed Dan Coats as Director of National Intelligence.

READ MORE: Fort Worth Police Investigating Officer-Involved Shooting Outside Home

If Ratcliffe, who serves in the 4th Congressional District, is confirmed by the Senate, Governor Greg Abbott will call for a special election.

U.S. Rep. John Ratcliffe (R-TX) speaks during a hearing before the House Judiciary Committee June 28, 2018 on Capitol Hill in Washington, DC. The committee held a hearing on “Oversight of FBI and DOJ Actions Surrounding the 2016 Election.” (Photo by Alex Wong/Getty Images)

Neal Katz, executive director of the Collin County Republican Party, said, “I fully expect to see a mob of people running. I fully expect there to be a lot of competition. It’s going to be a hard-fought race.”

The 4th Congressional District spans 18 counties and extends as far east as Texarkana.

But most of the more populous counties are in North Texas.

Republican State Senator Pat Fallon, whose own district falls within Ratcliffe’s district, is interested in the seat, and Rockwall County Commissioner Dennis Bailey says he’s considering a run.

Two other Republican state senators whose districts fall in the congressional district, Bryan Hughes and Bob Hall, did not return calls from CBS 11 seeking comment.

Matthew Wilson, SMU Political Science Professor, said “The relevant action here is going to be in the Republican primary. That is where the next Congressman or woman is going to emerge from. The Democrats will have a candidate, but without much real chance.”

Ratcliffe won 76 percent of the vote in the general election last year, while Democrat Catherine Krantz earned 23 percent, and Libertarian Ken Ashby received 1 percent.

Krantz didn’t return our call seeking comment on whether she will run during the special election.

Republican John Cooper, who challenged Ratcliffe during the March, 2018 primary, didn’t return our call either.

READ MORE: Jamie Jaramillo Faces Capital Murder Charge In Shooting Death Of Mesquite Police Officer Richard Houston

Wilson said the president won’t have to worry about Republicans retaining the seat. “It’s precisely because he knows this appointment will not imperil a Republican seat. This seat is safe in GOP hands. It’s a relevant consideration especially when the margin in the House is pretty close and where a major Republican objective in 2020 is going to be to try to take back the House.”

Ratcliffe was unavailable for an interview Monday, but in a tweet Sunday night, Ratcliffe said, “President Trump’s call to serve in this role was not one I could ignore, and I am incredibly thankful to him for this great honor. I look forward to my new role with energy and focus. It has been the privilege of my lifetime to be the voice for the people of the Fourth District.”

Texas Senator John Cornyn made the following statement on Rep. Ratcliffe:

“For four and a half years, John has faithfully and diligently served the people of Texas’ fourth district in Congress. Prior to that he served with distinction as a United States attorney, prosecuting cases that spanned a wide spectrum of issues, including counterterrorism and national security. Mr. Ratcliffe is a member of the House Intelligence, Homeland Security, and Judiciary Committees; a pretty good portfolio for somebody who would be the next Director of National Intelligence, so he already has an understanding of the threats facing our country and the challenges that lie ahead. I’m confident he will continue Director Coats’ strong leadership as a nonpartisan, strong leader for the intelligence community.”

Sen. Cruz on Tuesday weighed in on the nomination and said:

“Rep. Ratcliffe is a good man and a friend who has served the people of Texas well, first as U.S. Attorney and then representing the 4th district as a Member of Congress and on the House Intelligence Committee. I believe the president made a strong choice, and I look forward to working with my Senate colleagues to get Rep. Ratcliffe confirmed.”

A member of both the House Judiciary and Intelligence committees, Ratcliffe made headlines last week after sharply criticizing former Special Counsel Robert Mueller’s Russia investigation.

Ratcliffe is also a former U.S. Attorney for Collin and Denton counties who also specialized in terrorism.

Wilson said, “Clearly, his going after Mueller at these hearings is what impressed Trump, caught his eye and made Trump believe he would be a good choice for an open position. He does have some relevant experience in terms of his House service as well as his prosecutorial background.”

Some Democrats are criticizing Ratcliffe including Democratic Senate Minority Leader Chuck Schumer, who tweeted, “It’s clear Rep. Ratcliffe was selected because he exhibited blind loyalty to President Trump with his demagogic questioning of Mueller.”

Senator Ron Wyden of Oregon and top Democrat on the Senate Intelligence Committee said, “Congressman Ratcliffe is the most partisan and least qualified individual ever nominated to serve as Director of National Intelligence.”

But Ratcliffe’s Republican colleagues in the House have praised him and his qualifications.

North Texas Congressman Ron Wright tweeted, “My colleague Rep. Ratcliffe is an outstanding choice to replace Dan Coats as Director of National Intelligence. Once again, POTUS has selected the best and brightest!”

MORE NEWS: Cyclist Killed After Car Hits Him On East Division Street In Arlington

Katz of the Collin County GOP is backing Ratcliffe, too. “I think it’s a good pick. I’ve had the pleasure of knowing John personally for years. He’s a down to earth person, a solid thinker. John knows his material. He knows intelligence. He knows fact. I think he did a great job as Congressman and I think he’ll do a great job in this position.”