President Donald Trump on Thursday lashed out against a sitting GOP senator and praised his primary opponent, demonstrating yet again his penchant for personally responding to criticism.
In an early morning tweet, Trump referred to Sen. Jeff Flake (R-Ariz.) as "Flake Jeff Flake," dismissing the senator's moderate stance on immigration as "weak." He dismissed Flake as "a non-factor in Senate," yet also claimed the senator was "toxic."
Trump also applauded Kelli Ward, a GOP primary challenger against Flake, who is up for re-election in 2018, in a race that many political observers anticipate will be close.
Earlier this summer, White House officials reportedly met with Ward as well as other potential primary challengers to Flake, according to Politico.
Flake, who did not support Trump in 2016, frequently criticizes the president. But as FiveThirtyEight noted, Flake has mostly voted in line with Trump's policies thus far, and he's voted in support of the president's Cabinet appointees and other top officials requiring Senate confirmation.
Trump often lambastes GOP lawmakers, to the consternation of party leaders. During Senate Republicans' thwarted attempts to repeal and replace the Affordable Care Act, he went after Sen. Dean Heller (R-Nev.), who had opposed the original bill. A pro-Trump political group took the unprecedented step of running ads against Heller.
Earlier this month, Heller, who is also up for re-election next year, received a primary challenger: Nevada businessman and Trump supporter Danny Tarkanian.
Trump's barbs against Flake comes as the president is scheduled to hold a campaign rally in Phoenix, Arizona, next week. On Wednesday, the city's Democratic mayor asked him to delay the rally, citing Trump's widely criticized response to last weekend's violence in Charlottesville, Virginia.
The president has also regularly attacked Arizona's other senator, John McCain, most recently because McCain cast the pivotal vote to sink Senate Republicans' revised health care bill last month.
McCain tweeted in support of Flake after Trump's criticisms Thursday morning:
This article has been updated with comment from McCain.