Donald Trump continues to lead his rivals nationally in the contest for the Republican presidential nomination, but his hold on the GOP electorate has weakened since the primary season began and the party is now deeply divided over his candidacy, according to a new Washington Post-ABC News poll.

Trump maintains the support of 34 percent of registered Republicans and Republican-leaning independents, compared with 25 percent for Cruz, 18 percent for Rubio and 13 percent for Ohio Gov. John Kasich.

Trump’s margin over Cruz has narrowed from 16 points in January to 9 today. As a succession of Republican candidates has quit the race, Cruz’s percentage has ticked up 4 points since January, Rubio’s by 7 and Kasich’s by 11. Trump’s has dipped by 3 points, within the poll’s margin of sampling error.

In the Democratic race, Hillary Clinton still leads Sen. Bernie Sanders, I-Vt., but her national margin is the smallest in a Post-ABC poll since the beginning of the campaign. The new poll shows Clinton the favorite of 49 percent of registered Democrats and Democratic-leaning independents compared with Sanders at 42 percent. That 7-point Clinton margin compares with her 19-point advantage in January.

That Trump is a polarizing figure within the Republican Party is no surprise, typified by the opposition among establishment and other Republicans that has intensified over the past few weeks. Only a bare majority (51 percent) of Republicans or Republican-leaning independents say they would be satisfied with the New York billionaire as their nominee, a noticeably smaller percentage than for Cruz (65 percent) or Rubio (62 percent), with Kasich in between at 56 percent.

Favorable ratings also indicate an increasingly tenuous standing within the party. In early January, Republicans’ clearly gave Trump more favorable than unfavorable reviews, 60 percent to 39 percent. That has narrowed to a 53-46 margin, with negative marks at their highest level in Post-ABC polling since he entered the race. Trump’s positive ratings also trail Cruz’s 64 percent and Rubio’s 63 percent.

The Post-ABC poll finds over half of Republicans and GOP-leaning independents think Trump is dishonest, does not understand their problems, lacks the right experience and does not have the right personality and temperament to be an effective president. By contrast, over 6 in 10 Republicans say Cruz is honest, empathetic and has the right temperament and experience; similar shares say Rubio the first three qualities, while half say he has the right experience.

In a hypothetical head-to-head test of strength between Trump and Cruz, Republicans say they prefer the Texas senator by 54-41 percent. Rubio is a narrower favorite in a one-on-one test against Trump, with a 51-45 percent edge. The survey did not test a Trump-Kasich faceoff.

The poll was conducted through a weekend in which Cruz won contests in Kansas and Maine, Trump won in Louisiana and Kentucky and Rubio won in Puerto Rico. On Tuesday, Republicans will cast ballots in Michigan, Mississippi, Idaho and Hawaii.

Next Tuesday – the first day states can award delegates on a winner-take-all basis – there will be contests in Florida, Ohio, Illinois, Missouri and North Carolina. By the end of that day, more than half of the 2,472 convention delegates will have been selected.

It is likely that, after those March 15 contests, Republicans will have the clearest sense yet of Trump’s overall strength as well as of the viability of his challengers. Cruz’s string of recent victories, including his home state of Texas a week ago, have elevated him as the leading rival to Trump. Rubio and Kasich need to win their home states or face pressure to quit the race.

Many now predict that the Republican contest will not be resolved before the national convention in July. But even many Republicans who say they would not be satisfied with Trump as the nominee appear uneasy about the efforts by leaders of the party to prevent him from winning. About half of all Republicans who are only “somewhat satisfied” or dissatisfied with Trump nonetheless oppose efforts by Republican Party leaders to prevent him from becoming the Republican nominee.

There is considerable talk now about a possible floor fight at the convention, should Trump arrive with the most delegates but lacking the 1,237 needed for a first-ballot victory. Some 42 percent of Republican voters currently support other candidates and say that, in that situation, the party should pick another nominee. But 53 percent either support Trump or say that leading the delegate count, even if short of an outright majority should guarantee victory.

Among all Americans, Trump currently has a more negative image by far than Cruz or Rubio or than Clinton. Two in three adults (67 percent) say they have an unfavorable impression of Trump, who has drawn controversy over months for attacks on illegal immigrants from Mexico, on Sen. John McCain of Arizona, on Fox New anchor Megyn Kelly, on a disabled reporter and on Muslims, among other targets.

None of the three other candidates tested – Clinton, Cruz and Rubio – had a net positive image, but all were viewed more favorably than Trump. Among all adults, 52 percent say they see Clinton unfavorably, 51 percent see Cruz negatively and 45 percent have a negative impression of Rubio. Clinton and Rubio have the least negative image overall.

The new Post-ABC survey shows a huge gender gap around Trump’s candidacy. He leads among Republican men with 44 percent, a roughly 2-1 margin over second-place Cruz. Among Republican women, however, he is the favorite of just 24 percent. His margin among GOP women against Cruz was 37-15 percent in January. Trump also has lost ground against Cruz among very conservative Republicans and among those with incomes below $50,000.

Matched against his remaining rivals, Trump continues to do slightly better among Republicans without college degrees than those with college graduates, although he has an edge with both groups. He has a wider lead among voters under age 50 than with older voters. Among white evangelical Christians, Trump narrowly trails Cruz, but among non-evangelicals and white Catholics, his lead is almost 2-1.

Matched directly against Cruz, however, Trump loses voters with or without college degrees, voters who see themselves as working-class and middle-class, and those with higher and lower incomes. Trump loses conservatives against Cruz, especially those who say they are “very conservative,” and the two tie among moderate and liberal Republicans.

Overall, Americans remain deeply pessimistic in attitudes about the federal government. Two in three offer negative reactions, including about a fifth who describe themselves as angry. Trump has tapped into that mood. The more dissatisfied people are with the federal government, the more they are likely to support his candidacy.

A similarly strong majority see the political system today as dysfunctional, even slightly more so than last fall. Trump does best among those who feel most strongly about the way the system works.

More Americans by far say they favor someone with experience in the system as the next president, rather than someone from outside the political establishment. Republicans, however, tilt more in the direction of an outsider. Among those who want someone from the outside, Trump has the support of nearly half. Among those looking for someone with experience, Trump runs fourth behind Cruz, Rubio and Kasich.

A similar pattern holds for two of Trump’s most controversial ideas – deporting all of the roughly 11 million undocumented immigrants currently living in the United States and temporarily banning Muslims from entering the country as a security precaution. Overall, Americans oppose both, while more Republicans favor than oppose them. Trump has big leads among those who support those policies, but those leads disappear among opponents.

The Post-ABC poll was conducted March 3-6 among a random national sample of 1,000 adults reached on land-line and cellular phones. The margin of sampling error for overall results is plus or minus 3.5 percentage points.

(c) 2016, The Washington Post · Dan Balz, Scott Clement