WASHINGTON -- US President Donald Trump declared victory in national midterm elections at a hostile news conference on Wednesday, claiming that Republicans beat expectations by retaining control of the Senate and thwarting the potential for an even larger blue wave over the House of Representatives.He said the White House enjoyed an "incredible" and "tremendous" election night. But Democrats won enough seats in the House to wrench control over the congressional chamber from Republicans, providing a check on Trump previously absent and robbing him of one-party rule across Washington.In taking back the House, Democrats will now be able to block party-line legislation and chair several critical committees with appropriations and subpoena power, making it difficult for the president to unilaterally decide what priorities to fund and opening him and his aides to investigation on countless fronts.Speaking with the press, Trump warned Democrats against that approach, threatening not to work with them if House leadership chooses to conduct particularly aggressive oversight."If they do that, then all it is is a warlike posture," Trump said.Some of the most important committees in Congress will now have Jewish chairmen. It is expected that Jerrold Nadler of New York will head the House Judiciary Committee, Nita Lowey of New York the Appropriations Committee, Eliot Engel of New York the Foreign Relations Committee and Adam Schiff of California the Intelligence Committee.Those committees will transform into battlegrounds for the Trump presidency in January, once the new Congress is sworn in. As early as Tuesday night, these four members were previewing their plans to subpoena the president and his aides for his tax returns and for documents on his family business ties overseas. They are likely to investigate the president's handling of hurricane response in Puerto Rico last year, his policy of separating migrant families at the border and his relationship with Moscow.They may also examine the president's payments to Stormy Daniels, a porn star and his alleged mistress before entering the White House, as well as his firing of former FBI Director James Comey. They could look at ethics compliance of his son-in-law, Jared Kushner, at Treasury Secretary Steven Mnuchin's business dealings, at the use of personal email for government business by White House staff, administration-backed voter suppression efforts, and at the politicization of scientific study at the Environmental Protection Agency.Democrats also won important gubernatorial races in states that voted Trump during the 2016 presidential race, including Wisconsin, Michigan and Pennsylvania. A Jewish candidate in Colorado, Jared Polis, won his race there and will become the nation's first openly gay governor. Those elected on Tuesday to governor's mansions will be empowered to guide redistricting after the 2020 national census comes in, affecting future control over the House.But Democrats did not take back the Senate, which means that Republicans will maintain power over nominations to powerful positions such as cabinet posts, ambassadorships and justiceships. Democrats lost seats they had previously held in Indiana, Missouri and North Dakota, allowing Republicans to increase their margin in the upper chamber.Trump responded to the results on Wednesday morning via Twitter, hailing a great victory and warning Democrats against using the House as a tool to investigate his administration into paralysis."If the Democrats think they are going to waste Taxpayer Money investigating us at the House level, then we will likewise be forced to consider investigating them for all of the leaks of Classified Information, and much else, at the Senate level," Trump stated. "Two can play that game!"Democrats did pick up one seat, however, electing the nation's latest Jewish senator in Nevada. Jacky Rosen, who once served as president of her congregation, comfortably defeated incumbent Dean Heller.Democrats' reentry into House leadership will be a test of the party's evolving stance on Israel as it seeks to differentiate itself from the president in power on foreign policy. Aid to Israel– including emergency aid in times of conflict– goes through the House, and votes on such aid were the subject of debate in several races across the country.But Israel advocates see a friend in Engel at the Foreign Affairs Committee. The veteran New York congressman has frequently led bipartisan legislation boosting Israel ties, and supported Trump's 2017 decision to recognize Jerusalem as Israel's capital.Nevertheless, a wing of the party that self-identifies as progressive, including such figures as Independent Vermont Senator Bernie Sanders and Democrat Alexandria Ocasio-Cortez, who won New York's 14th congressional district seat on Tuesday, advocate harsher policy on Israel over its presence in the West Bank and its military operations in the Gaza Strip.The party also continues to oppose the president's withdrawal from a 2015 international nuclear deal with Iran, and may use control of the House as a vehicle to undermine or probe his policy of "maximum pressure" on the Islamic republic.The American Israel Public Affairs Committee, which works toward bipartisan consensus on Israel legislation, praised the election results."Virtually all of the victors in this year's election have issued position papers and statements reflecting their strong commitment to strengthening the US-Israel relationship," their statement read. "AIPAC applauds the election yesterday of a solid pro-Israel Congress."Israel advocates prioritized two races throughout the midterms: The reelection of Democratic Senator Bob Menendez in New Jersey, who faced accusations of corruption but who has, in his capacity in the Foreign Relations Committee, been a staunch critic of Iran; and the defeat of Democratic House candidate Leslie Cockburn in Virginia, who wrote a conspiratorial book in the 1990s titled "Dangerous Liaison: The Inside Story of the US-Israeli Covert Relationship." They succeeded on both counts.Democrats considering a run for the presidency say they will decide how to proceed after Tuesday's election, and that field, as well, is expected to feature several Jewish contenders, including entrepreneur and former New York Mayor Mike Bloomberg; Los Angeles Mayor Eric Garcetti; former Starbucks CEO Howard Schultz; and Sanders, among others.They will enter a political environment infused with a virulent strain of antisemitism– a scourge that transformed the final days of the 2016 race after a mass shooting at a synagogue in Pittsburgh, Pennsylvania, last week, shook the nation.Several white nationalists, avowed neo-Nazis and "alt-Right" figures running as Republicans lost their election battles this cycle, among them Dana Rohrabacher of California, who befriended Holocaust deniers and Russian oligarchs; John Fitzgerald of California, himself a vocal Holocaust denier; Arthur Jones of Illinois, a former American Nazi Party leader; and Lena Epstein of Michigan, who invited a Jews-for-Jesus rabbi to lead prayer after the Pittsburgh massacre.But Congressman Steve King of Iowa, who this summer met with Austria's far-Right party and told Germans to stop apologizing for the Holocaust, won reelection.On the Democratic side, three women who have been harshly critical of Israel won House seats, including Ilhan Omar of Minnesota, who calls Israel an "apartheid regime;" Rashida Tlaib, the first Palestinian-American elected to Congress who has vacillated on support for a two-state solution; and Ocasio-Cortez, who has loudly criticized Israel for its policies in Gaza and the West Bank.In Florida, where a large percentage of American Jewish voters reside, Republicans secured two valued prizes: a Senate seat and a governor's mansion. Incumbent Democratic Senator Bill Nelson was narrowly defeated by former Governor Rick Scott, although the .4% voter margin likely will result in a statewide recount; and Andrew Gillum, who was running to become the state's first African-American governor, lost his race to Ron DeSantis, a Trump loyalist.Perhaps most consequential in Florida, however, was the passage of a state constitutional amendment that will grant convicted felons the right to vote after they have completed their sentences. State officials estimated that will add 1.5 million individuals to the voter roles by 2020– including 1 in 5 African-Americans living in the state– likely affecting the upcoming race there for president.