Originally published Tuesday, September 10, 2019 at 07:20p.m.

PHOENIX – Arizona Republicans told state election officials Monday they're scrapping their 2020 primary, joining GOP leaders in three other states that are forgoing a presidential nominating contest as President Donald Trump seeks re-election.

Long-shot candidates challenging Trump for the Republican nomination have objected to the moves in Nevada, South Carolina and Kansas to skip GOP primaries or caucuses next year.

Canceling nominating contests is not unusual for the party that controls the White House when an incumbent president is seeking a second term. Democrats in Arizona skipped presidential primaries in 1996 and 2012, and as did Republicans in 2004.

"Arizona Republicans are fired up to re-elect President Trump to a second term and will continue to work together to keep America, and Arizona, great," State GOP Chairman Kelli Ward said in a statement last week.

Challengers have emerged to Trump, including Weld and Joe Walsh, a former Illinois congressman. Others may join them.

Primary challenges to incumbents are rarely successful, and Trump's poll numbers among Republican voters have proved resilient.

Nonetheless, Trump aides are looking to prevent a repeat of the convention discord that highlighted the electoral weaknesses of Presidents George H.W. Bush and Jimmy Carter in their failed reelection campaigns.