Sen. Joe Lieberman (I-Conn.) may have softened his rhetoric toward the Obama administration after being welcomed back into the Democratic caucus, but he has not stopped being an occasional thorn in the president's side.

Lieberman announced Wednesday that the administration could be doing more to combat drug cartels, and, of all people, an old campaign trail ally -- Sen. John McCainJohn Sidney McCainMeghan McCain says Ben Carson should be developing brain cancer treatment, not working at HUD Graham urges Trump not to abandon infrastructure talks with Democrats Pelosi receives John F. Kennedy Profile in Courage Award MORE (R-Ariz.) -- agreed.

"Lieberman just announced at the hearing that the administration could do more to combat the drug cartels," McCain tweeted. "I agree."

The administration announced its response to the ongoing drug war in Mexico yesterday morning.