Political outsiders Donald Trump and Ben Carson topped another national poll of Republican voters Tuesday, as frustration with the party establishment, particularly in Congress, shows no signs of abating. Jeb Bush, meanwhile, is suffering a drop in his favorability ratings.

In the latest Monmouth University poll, Trump took 28 percent to Carson's 18 percent, followed next by Texas Sen. Ted Cruz with 10 percent. Below them, Carly Fiorina and Florida Sen. Marco Rubio earned 6 percent, while Bush received 5 percent. Former Arkansas Gov. Mike Huckabee and Kentucky Sen. Rand Paul both came in at 4 percent, while New Jersey Gov. Chris Christie had 3 percent. None of the other candidates earned more than 1 percent support. The latest survey is not one of the polls being used to determine who makes the cut at next week's CNBC debate.

In terms of favorability, most all the candidates remained steady, except for Bush. Just 37 percent saw the former governor in a positive light, while 44 percent had an unfavorable opinion of him. In the September poll, voters were split 41 percent favorable to 39 percent unfavorable, and in August, the numbers were higher, at 52 percent favorable to 30 percent unfavorable.

Meanwhile, 50 percent of the same group surveyed said that their national party is doing a bad job representing them in Congress, while 41 percent said it was doing a good job. Just 42 percent said they were very or somewhat satisfied with Republican leadership, while 57 percent said they were very or somewhat dissatisfied. A plurality of 39 percent said that more conservative members, such as those in the House Freedom Caucus, have too little power in Congress, while 25 percent said they have too much and 21 percent said they had the right amount.

Overall, Republicans appeared split over whether groups like the House Freedom Caucus should be able to do what they want, with 35 percent responding that way and 39 percent responding that GOP leadership should stand up to them on more occasions.

Asked whether Wisconsin Rep. Paul Ryan would be a good choice for the next speaker of the House, 45 percent said that he would and 13 percent said that he would not. But 42 percent did not have an opinion one way or the other.

The poll was conducted Oct. 15-18 via landlines and cellphones, surveying 348 registered voters who self-identified as Republicans or as independents leaning toward the Republican Party. The margin of error for the sample is plus or minus 5.3 percentage points.