Herman Cain in 2012. Trump likely won't nominate him to a Federal Reserve board seat now that Republican have voiced objections to the pick. (Jonathan Ernst/Reuters)

When it comes to how to govern, there is some daylight between President Trump and Senate Republicans. Just look at the many Trump nominees members of his own party have tanked.

Even as they confirm judges at a record pace, nearly half of Republican senators have held, blocked or threatened to block a Trump nominee, according to publicly available information compiled by Senate Democrats. This week, enough Republican senators have said they won’t vote for Herman Cain to be on the Federal Reserve’s board of governors to sink the 2012 GOP presidential candidate’s nomination before it was official. In a closely divided Senate, just a few Republican no votes is enough to effectively kill a nomination.

Some fights stem from natural tension between the legislative and executive branches. Opposing nominations is a tool senators have to force the White House to listen. Last year, Sen. Cory Gardner (R-Colo.) said he wouldn’t vote for any Justice Department nominee in protest over the Trump administration’s marijuana policy.

But a sizable number of these nomination battles were born from significant Republican concern that Trump’s picks aren’t fit for the job. Here’s a list of the most notable flame-outs:

Cain to the Federal Reserve’s board of governors: Trump hadn’t formally nominated Cain to the independent agency, but Republicans almost immediately balked at the idea when Trump brought it up earlier this month.

Cain was forced out of the 2012 presidential race over multiple accusations of sexual misconduct and harassment, which he denied. Trump’s pick also alarmed Republicans because Cain is a politician with no experience setting monetary policy, a decidedly apolitical job. Senate Majority Leader Mitch McConnell (R-Ky.) declined to offer his support for Cain, and four Senate Republicans said they won’t vote for him, sinking his nomination before it happened.

Ronny L. Jackson to lead the Department of Veterans Affairs: Last spring, Trump nominated the White House doctor for his job, and it went badly from the start. Republicans and Democrats were concerned Jackson had no experience managing people, let alone a complicated federal agency. Then, Sen. Jon Tester (D-Mont.) released a list of allegations that Jackson’s colleagues had raised about his workplace conduct. They included everything from handing out prescriptions freely, to allegations of multiple incidents of drunkenness on duty. Senate Veterans’ Affairs Committee Chairman Johnny Isakson (R-Ga.) stopped the nomination process in its tracks over the allegations, forcing Jackson to withdraw.

Thomas A. Farr to a U.S. District Court seat: Trump nominated this North Carolina lawyer to a key seat on a federal court. But Farr lost support from two Republican senators over questions about his involvement in potential intimidation of black voters in the 1980s. The Washington Post uncovered a Justice Department memo detailing how Sen. Jesse Helms (R-N.C.) mailed postcards throughout the state that Justice said were sent to dissuade black voters from voting. Farr was a lawyer for the Helms campaign. He denied knowledge of the postcards, but the memo was enough for Sen. Tim Scott (R-S.C.), the Senate’s only black Republican, to say he couldn’t vote for him.

Ryan Bounds to be a judge on the U.S. Court of Appeals: Another Trump nominee to an influential court had his nomination withdrawn over concerns about his views on race. Bounds apologized for writings in the Stanford Review making fun of groups concerned with racial issues, comparing their tactics to “Nazi book burning.” Here, too, Scott was the key vote opposing him, and he managed to sway Sen. Marco Rubio (R-Fla.) as well.

Brett Talley to a U.S. District Court seat: This Alabama lawyer’s nomination was withdrawn in the summer after it was reported that he defended earlier versions of the Ku Klux Klan in a 2011 online comments section. He also had never tried a case before, and the American Bar Association said he was not qualified for the federal bench. Senate Judiciary Chairman Charles E. Grassley (R-Iowa) told the White House to “reconsider” his nomination, a not-so-gentle-nudge to drop this pick.

Jeff Mateer to a U.S. District Court seat: His 2017 nomination to be a judge in Texas was withdrawn after CNN uncovered he had said transgender children were part of “Satan’s plan” and had defended the questionable practice of conversion therapy. Grassley told the White House to “reconsider” his nomination as well.

Matthew Petersen to a U.S. District Court seat: Petersen’s nomination ran off the rails during his 2017 confirmation hearing, where he was unable to answer fairly basic questions from a Republican senator about how to be a judge. Sen. John Neely Kennedy’s (R-La.) questions went like this:

Had Petersen ever handled a jury trial? "I have not," the nominee responded.

Civil? No. Criminal? No. Bench trial? No. State or federal court? No.

How many depositions had he taken — fewer than five?

"Probably somewhere in that range," Petersen said.

Had he ever argued a motion in state court? Federal court? No on both counts.

Kennedy then asked the last time Petersen had read the Federal Rules of Civil Procedure — the standards that govern civil cases in U.S. district courts.

“In my current position,” Petersen stuttered, “I obviously don’t need to stay as invested in those on a day-to-day basis, but I do try to keep up to speed.”

Petersen withdrew his nomination a day after a video clip from the hearing surfaced.

Scott Garrett to lead the Export-Import Bank: Trump nominated the former New Jersey congressman in 2017 to lead this development bank even though Garrett had been an opponent of the bank when he was in Congress. A Republican-controlled committee reviewing his nomination voted against him, despite Trump vocally supporting Garrett.

Andrew Puzder to lead the Department of Labor: This was one of the earliest nominations Republicans helped tank, and it was for a Cabinet position. Republican senators said they couldn’t support the fast food CEO to run the nation’s labor agency, given he had employed an undocumented housekeeper.

This post will be updated as needed.