Sen. John McCain (R-Ariz.) Wednesday became the first White House candidate to call for Sen. Larry Craig (R-Idaho) to resign because of Craig’s guilty plea to charges of improper conduct in an airport restroom.

McCain’s call, reported by CNN, followed one from Rep. Pete Hoekstra (R-Mich.), who had earlier today become the first member of Congress to publicly call on Craig to resign.

“Senator Craig pled guilty to a crime involving conduct unbecoming a senator,” Coleman, who faces a reelection battle next year, said in a statement. “He should resign.”

“The voters of Idaho elected Senator Craig to represent their state and will decide his future in 2008 should he fail to resign,” Hoekstra said in a statement. “However, he also represents the Republican Party, and I believe that he should step down as his conduct throughout this matter has been inappropriate for a U.S. senator.”

Senate Republican leaders have called for an Ethics Committee investigation into the incident, but Hoekstra is the first member of Congress to call for the resignation.

In a news conference in Boise Tuesday, Craig said he would like to finish out his term through 2008, but will make a decision about his political future in September.

“There are still goals I would like to accomplish, and I believe I can still be an effective leader for Idaho,” said Craig.

The call by McCain indicates that the Craig drama is playing out against the backdrop of the Republican primary campaign.

Hoekstra is a member of Mitt Romney’s presidential campaign, as Craig was until Monday. Hoekstra is a Michigan co-chair of Romney’s campaign.

Craig resigned from his position as co-chair of Romney’s campaign after the disclosure of his arrest and guilty plea, and Romney called Craig’s behavior “disgusting.”