TEXAS (CBSDFW.COM) — Texas Democrats Beto O’Rourke and Julian Castro face different challenges as they try to build momentum for their Presidential campaigns.

O’Rourke, the former El Paso Congressman, already qualified for next month’s debate in Houston, but analysts say he needs to stop his slide in the polls and fundraising.

Analysts say Castro, the former San Antonio Mayor and HUD Secretary for President Barack Obama, needs to find a way to qualify for the next debate.

SMU Political Science Professor Cal Jillson said he was better last night even than the first debate.

Castro continues to win praise for his debate performance Wednesday night, when he went head to head against former Vice President Joe Biden over illegal immigration.

“The Secretary, when we sat together in many meetings, I never heard him talk about any of this,” Biden said.

And Castro’s response is being deemed the best line of the night.

“First of all Mr. Vice President, it looks like one of us has learned the lessons of the past and one of us hasn’t,” he said.

That line drew applause in Ford Theater in Detroit, where the debate took place.

Jillson says, “Julian Castro got off a very good line.”

But Jillson says even with that good line, Castro may not move the political needle to boost his poll numbers enough so that he qualifies for next month’s debate in Houston.

He says Castro must get on as much tv as possible.

“You’ve got to decide what your issue is and for Julian, it is immigration, So what are you going to say about immigration that attracts enough attention to you of a positive sort that it can move you up in the polls,” Jillson said.

And as for O’Rourke, he said while he did better in his second debate than the first, he hasn’t been the same since he attracted sharp criticism for standing on restaurant counters and his overall manner early-on.

In March, President Donald Trump mocked O’Rourke after watching him campaign.

“I saw his hand movements, I’ve never seen such hand movements,” Trump said. “Is he crazy or is that just the way he acts?”

Jillson said O’Rourke changed his style and disappeared.

“He’s never really recovered,” he said.

The SMU Professor said O’Rourke needs to somehow recapture the same energy he exhibited last year when he ran for U.S. Senate and nearly defeated Ted Cruz.

“That needs to be his signature, but people need to think that passion and energy are well-directed toward issues they care about,”Jillson said.

He followed by saying O’Rourke must find a way to break-through during next month’s debate if he wants to make it to the Iowa caucuses in February.

As for Castro, he has until the end of this month to move up to two percent in four polls so he can qualify for next month’s debate.