He says the bruising Republican primary, in which Braun and Congressmen Todd Rokita and Luke Messer each campaigned as unswerving backers of President Trump, suggests a misunderstanding of the job they're seeking.
Rep. Todd Rokita, R-4th District, had 29.5 percent as of 8:54 p.m., according to Politico, and Rep. Luke Messer, R-6th District, came in with 29.4 percent of the vote.
The 64 year-old local businessman owns Meyer Distributing and Meyer Logistics in Jasper, and entered the Indiana General Assembly as a state representative in 2014, representing District 63, before resigning in November 2017 to focus on his run for U.S. Senate.
"Mike Braun raises taxes like a Democrat so it's not a surprise he votes for Democrats, too", a Rokita spokesperson said of the report. Braun will take on incumbent Democratic Sen. Donnelly is one of 10 Democratic senators up for re-election this year in states President Donald Trump won in 2016.
The Herald Bulletin will update this story.
Donnelly, a moderate Democrat, was elected in 2012.
He'll now face Donnelly in November's general election.
"This is just the start of what President Trump can accomplish if he has the leaders that support him in Washington", Messer told Reuters after a campaign event in Carmel, Indiana.
In the final days of the race, an all-out battle between Blankenship and Republican leadership erupted after the coal CEO ran ads with racially-charged attacks on Senate Majority Leader Mitch McConnell's Asian in-laws.
Also in OH on Tuesday, Republican Mike DeWine and Democrat Richard Cordray won their party's primaries in the race to succeed term-limited GOP Gov. John Kasich.
Trump won West Virginia by 42 points in the 2016 election.
"Senator Donnelly is just another career politician who has spent almost his entire career in politics and government", Braun said in his statement.
The race will be a key one in deciding whether Democrats have a shot at winning the Senate. He says he hopes Rokita and Messer will rally behind him for what he notes is their common goal of defeating Donnelly. He also has a master's degree in economics from the Harvard Business School before serving three years in the Indiana House of Representatives from 2013 to 2017.
Indiana Republican Party Chairman Kyle Hupfer issued a statement Friday saying that no matter who won the GOP primary election, the nominee will be "a strong conservative" and "a steadfast supporter of the Trump-Pence agenda" and will have "a track record of delivering real results" in Congress, the General Assembly or the private sector.
IN is reliably Republican and is home to Vice President Mike Pence.
"When you've got a three-way race that's close, that means you might have two-thirds of the voters and two-thirds of the backers who aren't really sold on the victor even if they sincerely dislike and want to get rid of the incumbent", said Helmke, who directs the Civic Leaders Living-Learning Center at Indiana University in Bloomington.