WASHINGTON — Public support for Israel among Americans has remained strong through the most recent violence in Gaza, surveys have shown, though the attitudes of younger Americans and Democrats are less pro-Israel than they were during previous fighting.

Four weeks of nearly ceaseless rocket fire from Gaza and Israeli attacks there, in which more than 1,500 Palestinians and at least 65 Israeli soldiers and civilians have died, produced only a slight variation in public views that historically have favored Israel.

According to a Pew Research Poll released Monday, 40 percent of Americans blame Hamas for the fighting, while 19 percent blame Israel. The results are similar to those of a poll conducted by Pew in January 2009, during a previous Israeli incursion into Gaza, when 41 percent blamed Hamas and 12 percent blamed Israel.

“It’s a pro-Israel public,” said Alec Tyson, a senior researcher at Pew Research Center who worked on the most recent survey.

Research does show, however, that support for Israel is becoming increasingly partisan.

Another Pew poll, released last month, found that the gap between Republicans and Democrats on sympathy with Israel is at its widest since the 1970s.

Seventy-seven percent of Republicans said they sympathized more with Israel, compared with 44 percent of Democrats.

Democrats were roughly split on placing blame for the current conflict, with 29 percent saying Hamas was more responsible, 26 percent saying Israel was at fault, and 27 percent saying they were unsure. Among Republicans, support for Israel was stauncher, with 60 percent saying Hamas is responsible.

As a whole, about a quarter of people questioned say Israel has gone too far, the same as in 2009.

But Americans in general are less likely today to say Israel’s response to Hamas has been appropriate than they were five years ago — 34 percent this year, compared with 50 percent then. More said they were unsure of the appropriateness of the Israeli response, 24 percent, than in 2009, 19 percent.

Fifteen percent of those questioned said Israel should be more aggressive toward Hamas, up from 7 percent in 2009.

Young Americans, ages 18 to 29, were the most likely to report they were unsure if Israel’s response was appropriate, 32 percent, and more blamed Israel, 29 percent, than blamed Hamas, 21 percent.

While the Pew Center study found slightly shifting attitudes toward the conflict among so-called millennials — people born in the late 1980s and 1990s who are now in their 20s — researchers cautioned that those attitudes are likely to change as the people age.

“There’s potential for them (young people) to drive change, but there is also a potential that their own views will change,” Tyson said.