While President Donald Trump repeatedly rails against a caravan of undocumented Central American migrants attempting to reach the United States, Democrats are sticking to poll-tested campaign issues like health care with fewer than two weeks to go before midterm elections that will determine which party controls both houses of Congress.
"The caravan — look, that is an assault on our country," Trump said in Houston late Monday at a rally for Republican Senator Ted Cruz of Texas. "And in that caravan you have some very bad people. And we can't let that happen to our country."
In Virginia, Republican Senate candidate Corey Stewart seized on the caravan to blast his opponent, Democratic incumbent Tim Kaine.
"Tim Kaine is inviting this invasion into our country," Stewart tweeted. "@timkaine & his fellow socialists are openly calling for these invaders to violate our laws & smash through our borders."
"The timing [of the caravan] works well for Republicans," said Molly Reynolds, a fellow at the Washington-based Brookings Institution. "Republicans have been somewhat concerned about the level of enthusiasm among their base voters in 2018. So, in that sense, it [highlighting the migrant caravan] is really a tactic to motivate the base."
Many Democrats have not commented on the caravan other than to accuse Republicans of political games.
In a joint statement, Senate Minority Leader Chuck Schumer of New York and House Minority Leader Nancy Pelosi of California said Trump "is desperate to change the subject from health care to immigration because he knows that health care is the number one issue Americans care about."
The Democratic leaders added, "Democrats are focused like a laser on health care and will not be diverted."
Asked about the caravan, California Democratic Senator Kamala Harris on Monday told reporters, "What the people of our country want is leaders who are focused on the challenges that they face every day … not vilifying some group for the sake of fear-mongering and politics."
"What Democrats have decided to do in prosecuting the midterm campaign is focus on health care in particular and other issues that affect everyday Americans," Reynolds said. "They have created a pretty sizable lead in generic ballot polls. So some Democrats ask, 'Why change what's been working so far?'"
Human rights groups dispute Trump's assertions that the caravan includes criminals and Middle Easterners — claims for which he has provided no proof. Numerous migrants interviewed by reporters covering the caravan have maintained they seek a better and safer life in the United States.
Related: Faces in the Crowd: The Honduran Caravan photo gallery
The caravan and the election
Trump's often stark and unsubstantiated pronouncements on illegal immigration helped propel him to the Republican presidential nomination in 2016 and were credited with boosting Republican turnout in the general election, in which Trump defeated Democrat Hillary Clinton.
Reynolds said the president's anti-caravan rhetoric may mobilize core Republican voters once again this year, but argued that images of the caravan blanketing American news channels call into question Trump's warnings of a dire threat to U.S. security.
"It is worth noting that a lot of the images of the folks in the caravan are of women and young children who are fleeing violence. So it's not entirely clear to me that people aren't going to view them somewhat sympathetically, particularly after the crisis over the summer involving family separations at the [U.S.-Mexico] border."
The caravan, and Trump's statements about it, have received blanket coverage by some cable TV outlets and led many network news broadcasts in recent days, crowding out coverage of Democrats' favorite themes ahead of the November elections. The trend has not gone unnoticed by some progressive and Democratically-aligned commentators.
"The saturation coverage of this caravan, based on Trump's grotesque lies …is more grossly irresponsible than the panic-laced coverage of Ebola [cases in the United States] in 2014," tweeted Brian Beutler, editor-in-chief of Crooked Media, a news and opinion website.
Republicans, meanwhile, are eager to highlight a drama-filled real-time event tied to America's larger conversation about illegal immigration, an issue they believe puts Democrats on the defensive.
"You're going to choose between Republicans who will secure the border, versus Democrats who want to open the border," Texas Governor Greg Abbott said at the Cruz rally.