Incumbent U.S. Rep. Jim Baird commands overwhelming trader consensus at 97.6% implied probability to win Indiana's 4th Congressional District Republican primary on May 5, driven by his established record since 2019 in this deep-red district rated Trump +29. Despite challenges from state Rep. Craig Haggard, who secured endorsements from figures like Attorney General Todd Rokita in late March and faced $200,000 in anti-Baird PAC spending in April, Baird benefits from incumbency advantages, superior fundraising, and limited challenger visibility in a low-turnout primary. John Piper trails far behind at 0.7%. Upsets remain possible via late voter mobilization among conservative critics labeling Baird a RINO over immigration stances or unforeseen scandals, though historical base rates favor incumbents in safe seats.