– With about 4½ months to go until a midterm election that will determine whether Democrats gain power to check President Donald Trump, voter interest in the contest has reached historic highs, with far more intense focus than usual on one subject: the president.

Midterm elections often act as a referendum on whoever occupies the White House, but in most election years, many voters don't view their ballot that way. This year, they do: Some 60 percent say they view their midterm vote as a ballot essentially against (34 percent) or for (26 percent) Trump, according to a newly released survey from the nonpartisan Pew Research Center. That makes Trump a bigger factor in the midterm than any president since Pew first asked the question during President Ronald Reagan's first term.

The new survey highlights how much the national, partisan contest now outweighs local issues in voters' choice for Congress: Nearly three-quarters of voters on both sides of the partisan divide said they cared which party will end up controlling Congress — a significantly larger share than in previous elections.

The poll also pointed to a key group for Democratic hopes: younger women. Nearly 7 in 10 women younger than 35 said they favored a Democrat for Congress, and 4 in 10 said they saw their vote as one against Trump. Only about 1 in 10 said they thought of their vote as a ballot for Trump.

Overall, Democrats continue to hold an edge over Republicans in the fight for Congress, both in enthusiasm and voter preference, but the advantage remains small enough that the outcome, especially for the House, remains uncertain.

When asked which party's candidate for Congress they supported or leaned toward this year, voters surveyed by Pew sided with the Democrats by 5 percentage points, 48 percent to 43 percent.

Good economic news has buoyed Republicans, with voters giving the GOP an edge on managing the economy after several years in which neither party had an advantage on that topic.

On most other issues, including the two that voters most often said they want candidates to talk about — health care and immigration — a majority preferred Democrats.

The poll was conducted June 5-12, so it pre-dated the current controversy over the Trump administration's splitting up of families of immigrants caught trying to cross the border illegally. Even so, immigration was the top issue that the public cited when asked to name the most important problem facing the country. It was mentioned by 12 percent. Race relations and racism came in second, cited by 8 percent. Only 6 percent named the economy — a sharp contrast from only a few years ago.

The overall 5 percentage-point Democratic lead in the survey is consistent with other recent polls that have found, on average, that Democrats have an advantage of about 7 percentage points on the so-called generic ballot. That's around the level that, if history holds, would indicate a small Democratic edge in the battle for control of the House.

The generic ballot question typically has provided a fairly accurate election forecast. Democrats generally need a significant majority in the total vote nationwide in order to win a majority of the House — in part because of gerrymanders that favor Republicans and in part because Democratic voters, concentrated in cities, dominate fewer geographic districts.

The contest highlights a now-familiar divide along lines of race and education.

Republicans have a strong lead on the generic ballot, 57 percent to 34 percent, among white voters who did not graduate from college. Democrats have a smaller edge, 53 percent to 41 percent, among whites who have a college degree. They have large margins among Latino (63 percent to 30 percent) and black (77 percent to 16 percent) voters. Democrats also have a strong lead (57 percent to 37 percent) among voters younger than 35; voters 35 and older split closely between the two parties.

Republicans have a small advantage, 49 percent to 43 percent, among men, which is fairly consistent regardless of age. While women younger than 35 favor the Democrats by a large margin, among women 35 and older, the Democrats have an advantage, but a much smaller one.

In special elections over the past year, Democratic turnout has exceeded its usual level, and the poll finds some evidence that could continue into the November election. Among people who said they favored a Democrat for Congress, 55 percent said they were more enthusiastic than usual about voting. That's a much higher level than at similar points before the 2010 and 2014 midterms, both of which saw big losses for the Democrats.