There's no question in my mind that David Duke's decision to run for the Senate as David Vitter's replacement is the direct consequence of Donald Trump winning the Republican nomination.

Washington Post:

Former Ku Klux Klan leader David Duke on Friday announced he will run for U.S. Senate, linking his decision to Donald Trump’s bid for the presidency.

Saying he was “overjoyed” at Trump’s successful campaign to be the Republican party’s presidential nominee, Duke said he will advocate for the “rights and heritage of European Americans” in Congress.

“We must stop the massive immigration and ethnic cleansing of people whose forefathers created America,” Duke said in a video posted to his website.

The GOP is now the Party of Trump, and David Duke is taking full advantage.

Here is his announcement video, via Twitter:

I am Running for U.S. Senate Watch the video! https://t.co/mOvc4CaPfx

— David Duke (@DrDavidDuke) July 22, 2016

edit: And of course he absolutely loved Donald Trump's speech last night..

Great Trump Speech, America First! Stop Wars! Defeat the Corrupt elites! Protect our Borders!, Fair Trade! Couldn't have said it better!

— David Duke (@DrDavidDuke) July 22, 2016