Donald Trump Jr. took on Republican Rep. Justin Amash on Twitter Thursday and pushed for a primary challenge, after Amash became the first GOP House member to call for the impeachment of President Trump.

Amash called for Trump's impeachment in May and accused Attorney General William Barr of misrepresenting the final findings of the Mueller report.

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Amash announced he would be leaving the conservative House Freedom Caucus on Monday, which he co-founded -- after leadership reacted negatively to his comments. Amash claimed his exit was voluntary and will help avoid unwanted distractions.

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Trump Jr. shared a "Political Polls" tweet Thursday, showing Amash down 16 points to state Rep. Jim Lower and said he's looking forward to primary season in Michigan's third congressional district.

Amash replied less than two hours later and quoted a line from Trump Jr.'s email chain, which he released in 2017 as part of the Russia investigation.

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The president is reportedly considering joining the primary effort against Amash and has discussed the issue with several prominent figures, including Vice President Mike Pence and Freedom Caucus co-founder Rep. Mark Meadows.