And Karlyn Bowman, a senior fellow with conservative think tank the American Enterprise Institute (AEI), said the stakes were high prior to Tuesday’s vote, which she said amounted to a “referendum on the President”.
The United States confirmed yesterday it was deploying 5,200 troops to help secure the border, many more than expected as Mr Trump takes an uncompromising approach ahead of Tuesday’s crunch vote.
Ms Bowman said: “It’s become a highly politicised issue.
“It’s hard to be sure but stories about illegal immigration tend to benefit the Republicans more.
“So if that becomes the story, then that could play into Trump’s hands and be a vote winner for him.
“It comes down to perceptions, of course, and it varies on a state-to-state basis.”
According to a Pew Research Center survey conducted in late September and early October, 75 percent of Republican voters said illegal immigration is a very big problem, compared with 19 percent of Democratic voters.
The caravan has swelled in numbers since it started out on October 12 in the Honduran city of San Pedro Sula.
The deployment will create an active-duty force comparable in size to the US military contingent in Iraq, as Trump’s administration draws attention to the caravan, which UN estimates numbers more than 7,000 people, including many children.
General Terrence O’Shaughnessy, the head of US Northern Command, said 800 US troops were already en route to the Texas border and more were headed to the borders in California and Arizona.
Writing on Twitter yesterday, Mr Trump said the military would be waiting for the procession.
He added: “Many Gang Members and some very bad people are mixed into the Caravan heading to our Southern Border.
“Please go back, you will not be admitted into the United States unless you go through the legal process.
“This is an invasion of our Country and our Military is waiting for you!”
However, others have accused him of using the issue for political purposes, with Shaw Drake, policy counsel for the American Civil Liberties Union Border Rights Center in El Paso, Texas, saying: “President Trump has chosen just before midterm elections to force the military into furthering his anti-immigrant agenda of fear and division.”
Meanwhile, Ms Karlyn also emphasised the significance of the midterms, saying: “We always say this is the most important election yet but this one really is.
“This is a refendum on President Trump and if the Democrats can gain control of the House then they can investigate and possibly move to impeach him.
“The House is the really significant battleground this time around. The Senate is likely to remain unchanged and while the 39 gubanatorial battles will see big changes, that’s kind of stayed under the radar.
“It will be interesting to see how Mr Trump reacts if the Republicans do lose the House.
“I suspect if he wins it will because if him, but if he loses it will be somebody else’s fault.”