President Trump warned Saturday that if Democrats take back Congress in November, it will be a "a bright flashing invitation to every human trafficker, drug trafficker."

Trump said the "computer age" has allowed human traffickers to flourish and that a Democratic-controlled Congress would only exacerbate that problem.

[New: Trump: 'Blame the Democrats' for assault on the southern border]

The president stumped Saturday in Nevada for Sen. Dean Heller, R-Nev., and GOP gubernatorial candidate Adam Laxalt.

Trump spent a good portion of his speech Saturday telling Nevadans the same message he has attempted to drill into voters for the past few months: Democrats are the party of open borders, crime, and illegal immigration. The president wants voters to see stark contrasts between the Republican candidates, who support the president's border wall and immigration platform, and Democrats, who are unanimously opposed to GOP immigration policies.

Less than 24 hours before Trump took the stage in Nevada, he told supporters in Arizona Friday evening that "Democrats believe our country should be a giant sanctuary city for criminal aliens." Trump said that the U.S. should indeed be a sanctuary, but only for "law abiding citizens."

Trump also floated for the first time this week what appears to be the Republican rallying cry in the final weeks leading up to the midterms: "Democrats create mobs, Republicans create jobs."

Conventional wisdom and polling has Democrats taking control of the House in November, but Republican candidates and strategists are looking at local polls that show many races are still within the margin of error. For Republicans to maintain control of the House, they will need many of those races sway in their favor.