"To be honest, I'm not looking to give them any credibility", he added. "They have no credibility".
He joins former MA governor Bill Weld, who launched a bid against Trump in April seeking to appeal to traditional Republican voters, and former IL congressman Joe Walsh, who announced last month that he will challenge the president not from the center but from the right and on moral grounds.
Sanford also spoke against Trump's trade war with China.
Republican politician Mark Sanford speaks at OZY Fest in Central Park in NY on July 21, 2018.
Prior to the official announcement, Trump took aim at Sanford, foreshadowing the attacks to come by branding the former governor and congressman "Mr". There have also been reports tracing as far back as past year that Ivanka Trump plans to run for president in the future and has ambitions of becoming the first female president and possibly the first Jewish president, too.
South Carolina GOP Chairman Drew McKissick, Nevada GOP Chairman Michael McDonald, and Kansas GOP Chairman Michael Kuckelman are pointing to the cost savings of canceling their primaries, a move that will free up funds to use in support of candidates in other races.
Asked about his primary challengers as he walked to a waiting Marine One on Monday, Trump responded he doesn't know them, before giving very strong descriptions of his rivals' weaknesses.
"The four states that canceled it don't want to waste their money".
In an exchange with reporters after the event, Parscale declined to say whether he thinks Trump's children might run for office, saying only, "I think they are all wonderful people with. fantastic capabilities", the AP reported.
He was followed by conservative radio host and former lawmaker Joe Walsh at the end of August.
But some state Republican parties, including in SC, have decided not to hold primaries in 2020 - to clear the path for Mr Trump and save money.
"This is wrong. This is undemocratic". It's what they do in places like Russian Federation and China.
MARTIN: Right. It's also interesting because, clearly, as Republicans, they feel like they can't defect to the Democratic Party.
MARTIN: Yeah. So presumably, though, that means he doesn't believe Bill Weld or Joe Walsh are serious primary contenders. What are you afraid of, Mr. No-Show? "Now more than ever, @realDonaldTrump, you can run but you cannot hide".
Republicans have held the district since 1963, and they are hoping President Trump's endorsement of Bishop will keep the seat within the GOP.
The polls were conducted before Walsh and Sanford entered the race and no polls have been conducted since then. "I think that as the Republican Party, we have lost our way", the presidential hopeful said in an interview with U.S. broadcaster Fox News.
MARTIN: So we heard Sanford there in that clip saying the words financial conservatism.
But Democrats are daring to hope for an upset that would build on their takeover of the House from Republicans in elections past year and make further inroads in "Trump country". "I have a unique vantage point and set of experiences-as a Governor, as a Member of Congress and as a taxpayer outside of politics".
"I don't need someone to take a room overnight at a hotel", he said.