Houston CNN  — 

President Donald Trump knows the November election is all about him. He worries his supporters do not.

“Pretend I’m on the ballot,” he says at most every rally, trying to awaken his supporters to the urgency of the fight for control of Congress.

Two weeks before Election Day, a new air of uncertainty hangs over the 2018 campaign that revolves almost entirely around the Trump factor.

A month ago, the President seemed all but resigned that Republicans would lose the House, two people who speak to him frequently tell CNN. But his outlook has brightened in recent days, increasingly insisting he can awaken his coalition to stop – or slow – a Democratic wave, they say.

“If anyone can save the House, he thinks he can,” a Republican congressman close to the President said. “He’s the only one who believes it’s really possible.”

While most presidents distance themselves from midterm elections to avoid nationalizing the races, Trump is doing the opposite. He’s all in, firing up loyal supporters and fierce critics alike.

“This will be the election of the caravan, Kavanaugh, law and order, tax cuts and common sense,” the President said to booming applause inside Houston’s Toyota Center on Monday, boiling down his closing argument for Republicans in one crisp sentence.

Here in Houston, the rally on Monday night is his 29th of the year. It follows a familiar pattern of much of his 2018 campaign travel: visiting red states filled with Trump admirers, hoping to minimize political harm by energizing his detractors.

But even in Texas, several Republican strategists expressed a palpable level of anxiety at what the President might say during his unscripted rally. Trump’s sharp rhetoric on immigration, two officials said, could awaken Hispanic voters or independents in key congressional races in the state.

“We were hoping he would go to West Texas for this rally,” a Republican strategist said, speaking on condition of anonymity to avoid being seen criticizing the President or the White House.

An analysis of Trump’s travel shows where he is – and isn’t – welcome. In deep-red Montana, for example, he’s staged three rallies to try to defeat Democratic Sen. Jon Tester in a race even most Republicans see as no easy task.

Yet he’s all but steering clear of Florida – holding no big rallies so far this fall, despite campaigning there just months ago during the GOP primary. Republican Gov. Rick Scott, who’s locked in a tight race to unseat Democratic Sen. Bill Nelson, has asked Trump to stay away, a GOP official said.

But as in many states, Trump remains a central theme of the race, as illustrated in dueling TV ads from Nelson and Scott.

“When President Trump asks for something that’s good for him and bad for Florida, I know what I’ll do. I’ll say no,” Nelson said in a recent ad. “And we all know what Rick Scott will do. He’ll say yes.”

Scott responded: “I’ll work with President Trump when he’s doing things that are good for Florida and America. And when I disagree, I have the courage to say so.”

So far, the President has agreed not to campaign in Florida, but he did visit the Gulf Coast this month to survey hurricane damage. A Republican official said Trump keeps asking about the race, saying he wants to do a rally in the final week for either the Senate or governor’s race.

The last time Trump spent so much time hopscotching from one roaring arena to another, he was on a victory tour, thanking voters who helped turn states from blue to red in his triumph over Hillary Clinton. But statewide GOP candidates are trailing in most of those new Trump states, including Pennsylvania and Ohio, Michigan and Wisconsin.

While the near-nightly Trump show is back, this time his rallies are no longer regularly seen live on cable television. Even his beloved Fox News had taken a pass for weeks – until Monday night, when the Houston rally aired from start to finish.

His devoted fans are still filling every arena to the brim, but White House aides said he has repeatedly expressed frustration that his speeches are not being televised.

That’s not to say, of course, that Trump isn’t still the central character of the midterm election campaign.

The President appears in nearly 20% of all political ads this year, according to an analysis of data from Kantar Media/CMAG, based on the top 100 most competitive House and Senate races.

So far this year, at least $55 million has been spent on pro-Trump ads, the analysis found, with $61 million on anti-Trump ads.

The White House is increasingly confident about keeping control of the Senate, largely cause of the blessing of geography, with the majority of competitive seats in red states. To most places, Trump’s message lingers far longer than he does because Republicans turn his rallies into 30-second commercials blasting the Democratic candidate.

“Phil whatever the hell his name is, this guy will 100% vote against us every single time,” Trump says in an ad, attacking Phil Bredesen, the former Democratic governor running for the open Senate seat in Tennessee against Republican Rep. Marsha Blackburn.

While Trump has said he will accept no blame if Republicans lose control of the House, he will have to deal with the consequences of a Democrat-controlled House investigating the White House.

Such talk has been all but suspended for now in the West Wing, two aides said, with the President not interested in discussing what happens beyond Election Day. He has previously told allies that Democrat-led impeachment or investigations could strengthen his hand going into 2020.

Whatever the outcome on November 6, the midterm election campaign has solidified Trump as the indisputable leader of the Republican Party. Even old rivals like Cruz now depend on Trump’s coalition for their own survival.

“I think it energizes people,” Cruz told CNN on the eve of Trump’s visit to Houston. “I think it’s going to help drive turnout. And this election is a turnout election.”

Asked whether Trump was the biggest factor, Cruz replied: “The President is certainly a factor in the election, but I think the biggest factor in Texas is the economic boom we’re seeing.”

CNN’s David Wright contributed to this story.