There are over 1,200 positions in the US government (not counting judges or military appointments) that require the US Senate to confirm a candidate nominated by the president. (These are a subset of about 3,700 positions that require the president to appoint someone, but most of the positions in this broader group don't require Senate confirmation.) Often, the people appointed to these positions have a reasonable degree of day-to-day discretion in decision-making: in that sense, as those inside the DC beltway like to say, "personnel is policy.: As President Trump pushes ahead with his proposed appointments, what is the historical record of success for such appointments in the US Senate? Anne Joseph O’Connell compiles the evidence in "Staffing federal agencies: Lessons from 1981-2016," a report written for the Brookings Institution (April 17, 2017).

Here's a figure showing the success rate of presidential appointments in receiving Senate confirmation going back to the 97th Congress, during the 1981-82 at the start of President Reagan's first term.
Executive Branch Failure Rates Transparent

I'll mostly leave it to readers to sort through the years and whether the president was facing a Senate of the same party. But a few points seem worth noting: 

1) It's common for presidents to have 20% or more of their nominees not make it through Senate confirmation, especially later in presidential terms. 

2) The share of presidential nominees not making it through US Senate confirmation has been rising over time, and for President Obama, 30% of his nominees didn't make it through the Senate. 


3) Perhaps unexpectedly, the share of President Obama's nominees who didn't make it through the Senate was only a bit higher during his last two years in 2015-2016, when Republicans controlled the Senate, than it was during 2013-2014, when Democrats controlled the Senate. Moreover, remember that in November 2013, the Democrats running the US Senate changed the rules so that it was no longer possible to filibuster presidential appointees. But as O'Connell points out: 
"Failure rates, however, increased for free-standing executive agencies, within and outside the Executive Office of the President, and for national councils. More surprisingly, confirmation delays for agency nominations increased across the board. For those successful 2013 nominations (a few of which were actually confirmed in December after the change), they took 95 days, on average. In 2014, delays ballooned to 150 days. Indeed, it was the biggest jump in any given year in an administration between any two presidents."
4) O'Connell also makes the interesting point that often about 15-20% of these theoretically appointed positions, or more, are not filled at any given time over the years. She writes that President Obama appointed fewer people, and as a result ended up leaving positions open more often. 
"Interestingly, President Obama submitted fewer nominations (2828) than any of the other two-term presidents. President George W. Bush submitted the highest (3459); Presidents Reagan and Clinton each submitted around 3000 (2929 and 3014, respectively).... President Obama submitted fewer nominations than his predecessors, allowing acting officials to fill in for many important positions. President Trump could follow suit."
My own sense is that far too many low-level nominations are held up for dubious and extraneous reasons by individual or small groups of senators. For example, late in the Obama administration the board that is supposed to oversee the US Postal Service had zero members out of the nine possible appointments. The reported reason is that Senator Bernie Sanders put a hold on all possible appointees, as a show of solidarity with postal workers. If it isn't obvious to you how Sanders preventing President Obama from appointing new board members would influence the US Postal Service in the directions that Sanders would prefer, given that President Trump could presumably appoint all nine members of the board, you are not alone. 

This system of 1,200-plus presidential appointments requiring Senate approval seems dysfunctional but that doesn't alter the reality that these 1,200-plus appointments are among the most important steps a president can make.