The survey shows Democrats holding narrow leads over their Republican rivals in Senate races in Arizona, Pennsylvania and Georgia, while the two rivals in Nevada are locked in dead heat. Former President Donald Trump has endorsed Republican candidates in all four races. Democrats hope to retain at least their slim majority in the Senate. The House is currently split 50-50 between the parties, with Vice Speaker Kamala Harris casting the tie-breaking vote. Republicans only need to win a single seat to take control. Flipping any of the Democratic-held seats in Arizona, Georgia or Nevada — or defending GOP-controlled Pennsylvania — would give Republicans a boost in their bid for a Senate majority. A Republican-controlled Senate could dash President Joe Biden’s hopes of passing major legislation in the final two years of his first term. Republicans are favored to win control of the House. The most promising result for Democrats in the new poll came in Arizona, where respondents gave incumbent Sen. Mark Kelly a 6-point lead, 51 percent to 45 percent, over Republican Blake Masters. That result, taken from 604 likely voters between Oct. 24 and 26, fell outside the poll’s margin of error of 4.4 percentage points. In Pennsylvania, Democratic Lt. Gov. John Fetterman had a similar-sized lead over Dr. Mehmet Oz, 49 percent to 44 percent. But the survey of 620 likely Pennsylvania voters was conducted from Oct. 24 to Oct. 26 — long before the two candidates met for a debate in which Fetterman, who is recovering from a life-threatening stroke, struggled to articulate his thoughts. The poll’s overall result showed a plurality of voters, 48 percent to 35 percent, believe Fetterman is healthy enough to perform the duties of a U.S. senator. But among those polled after the debate, many said they didn’t think he was healthy enough for the job. The Pennsylvania survey has a margin of error of 4.4 percentage points. Georgia, key to Biden’s 2020 victory over Trump and the Democratic takeover of the Senate, is now home to a competitive race between Democratic Sen. Raphael Warnock and Republican Herchel Walker. The latest poll shows Warnock leading Walker by just 3 percentage points, 49% to 46%, a margin narrower than the survey’s margin of error of 4.8 percentage points. In Nevada, meanwhile, incumbent Sen. Catherine Cortez Masto is trying to fend off a challenge from Republican political scion and former state attorney general Adam Laxalt. The Times/Siena poll shows the two candidates tied at 47 percent in the race, which is considered one of the GOP’s best chances to flip a blue seat. Pollsters surveyed 885 likely voters in Nevada between October 19 and 24. The results have a margin of error of 4.2 percentage points. Midterm elections, seen as a referendum on current political leadership, tend to discredit the party in control of the White House. The president’s party has lost seats in Congress in every cycle since 2002. Surveys consistently show that inflation and crime are near the top of voters’ lists of concerns. Republican candidates across the board have accused their Democratic opponents of being soft on crime. They have also pinned high inflation, a global phenomenon for the past two years, on the policies of Biden and the Democrats. The president’s low approval ratings, though somewhat improved from previous months, are seen as a potential draw for Democratic candidates fighting for survival in competitive swing-state races. The president’s unpopularity is strongest in the four states included in the latest Times/Siena poll, where his ratings are either at or below the national average, the paper said. But Biden, a Pennsylvania native who beat Trump there in 2020, has been campaigning in the Keystone State for Fetterman in recent days. Harris, first lady Jill Biden and former President Barack Obama also hit the trail in the final sprint to the Nov. 8 election to support Democrats.