DES MOINES — If he runs, former President Donald Trump is the odds-on favorite of Iowa Republicans to win the state’s first-in-the-nation presidential caucuses.If he doesn’t, it appears there will be a wide-open race for Iowa GOP support among the party hopefuls seeking to challenge President Joe Biden in 2024.A Victory Insights poll of 650 Iowa Republicans found that 61 percent said they will support Trump if he runs.