WASHINGTON—President Trump lashed out at Democrats on Thursday over the bipartisan spending bills currently making their way through Congress, and demanded that Republicans do more to ensure greater funding for border security, particularly for his proposed border wall with Mexico.

“I want to know, where is the money for Border Security and the WALL in this ridiculous Spending Bill, and where will it come from after the Midterms? Dems are obstructing Law Enforcement and Border Security,” he said in a tweet on Thursday morning....