"I believe he made the right decision for himself and for his district, but most importantly, I believe he made the decision in the best interest of his family", Whitver said of Dix's resignation.
"Iowans hold their elected officials to a high standard, and as elected officials, we have an obligation to lead", she said.
The 18-year legislative veteran is married with three children, according to his statehouse biography.
Dix has been under pressure in the past year for his role in the sacking of Kristen Anderson, a communications director who complained about lewd behaviour in the Republican Senate caucus office.
Throughout the video, the two are very close kissing making out several times.
State Sen. Rob Hogg confirmed to KCCI that the lobbyist in the video is Lindsey McCune.More news: Taliban seize district headquarters in Afghanistan's Farah province
Robert L. Palmer, director of government affairs and legislative counsel said in an email: "We are taking what we believe are appropriate actions, but because this is a personnel matter we can not comment further".
Senate Democratic Leader Janet Petersen of Des Moines issued a statement calling the video "a serious matter" that follows Dix's failure to take responsibility for the $1.75 million settlement that resulted from a sexual harassment brought by former Senate Republican staffer Kirsten Anderson.
The Senate Republic Caucus will meet on Wednesday to elect a new leader.
Schneider and the other Senate Republicans went into a private meeting early Monday afternoon with Dix where Dix told his peers he was resigning.
Dix had already been widely criticized by members of his own party for his handling of the sexual harassment problem in the Senate Republican caucus uncovered by a lawsuit brought by a former staffer. She was awarded $1.75 million past year.
Dix began serving in the Iowa Senate in 2011 and became majority leader in 2013.
Dix, 55, is a third-generation farmer whose district covers Butler, Grundy, Hardin and Story counties.
Anderson asserted she was sacked in 2013 after complaining of a toxic work environment in the Senate.