Washington (CNN) Former President Barack Obama spent a sizable amount of time in a speech he gave in Illinois on Friday criticizing Republicans in Congress and President Donald Trump, while stressing the importance of voting in the fast-approaching midterm elections.

His step back into the political arena offered a preview of his message for the fall's midterms.

Trump quickly responded on Friday, telling a crowd in Fargo, North Dakota, that he "fell asleep" watching Obama's speech.

The Republican National Committee, for its part, responded to Obama's speech by saying, "President Obama stepped back into the spotlight to make the case that our country is on the wrong track."

"2016 is over, but President Obama is still dismissing the millions of voters across the country who rejected a continuation of his policies in favor of President Trump's plan for historic tax cuts, new jobs and economic growth," RNC spokesperson Ellie Hockenbury said in a statement. "Democrats may have a new resistor-in-chief on the campaign trail, but they'll need more than a message of resist and obstruct to win this November."

Here are some of the Obama's sharpest attacks on Trump and the Republican Party in his speech at the University of Illinois at Urbana-Champaign:

1. "What happened to the Republican Party?"

The former Democratic President hit Trump and Republicans hard on a variety of issues including health care, voting rights, campaign finance laws, and the economy, arguing that some policies GOP leaders are pursuing today aren't conservative.

The former President questioned the GOP's approach to foreign policy, including its position on Russia, challenging climate change science, and embracing of conspiracy theories including those "surrounding Benghazi or my birth certificate."

2. "The politics of division and resentment and paranoia has unfortunately found a home in the Republican Party."

Obama argued that today's generation is the most diverse, "conditions that are ripe for exploitation by politicians who have no compunction and no shame about tapping into America's dark history of racial and ethnic and religious division."

3. "Republicans who know better in Congress, and they're there -- they're quoted saying, 'Yeah, we know this is kind of crazy' -- are still bending over backwards to shield this behavior from scrutiny or accountability or consequence, seem utterly unwilling to find the backbone to safeguard the institutions that make our democracy work."

He slammed congressional Republicans for not acting as a check on the Executive Branch.

4. "They're not doing us a service by actively promoting 90% of the crazy stuff that's coming out of this White House, and saying 'Don't worry, we're preventing the other 10%.' That's not how things are supposed to work. This is not normal."

Obama addressed the recent controversy within the White House surrounding The New York Times op-ed written by an anonymous senior Trump administration official. The op-ed author claimed there was a "resistance" of senior officials working in the White House to "frustrate parts of his agenda and his worst inclinations." Obama argued that this "not how our democracy is supposed to work."

5. "I know there are Republicans who believe government should only perform a few minimal functions but that one of those functions should be making sure nearly 3,000 Americans don't die in a hurricane and its aftermath."

Obama made mention of the death toll in Hurricane Maria which hit Puerto Rico last year. Puerto Rico's government raised its official Hurricane Maria death toll from 64 to 2,975 last month. The Trump administration was under fire from Democrats for its response and handling of recovery efforts on the island.

6. "How hard can that be, saying that Nazis are bad?"

Obama argued that, "We are supposed to stand up to discrimination and we are sure as heck to stand up clearly and unequivocally to Nazi sympathizers." In August 2017, Trump was criticized for saying there was "blame on both sides" for the violence at a white supremacist rally in Charlottesville, Virginia.

7. "It did not start with Donald Trump. He is a symptom, not the cause."

Obama argued that Trump is "capitalizing on resentment that politicians have been fanning for years, a fear, an anger that is rooted in our past, but is also borne in our enormous upheavals that have taken place in your brief lifetimes."

8. "You've got to do what the Parkland kids are doing. ... And they're not giving up until we have a Congress that sees your lives are more important than a campaign check from the NRA."

The student activists of Marjory Stoneman Douglas High School in Parkland, Florida, got a shout-out from Obama as he also attacked the conservatives in Congress who accept donations from the National Rifle Association. Following a February 14 massacre at the school, survivors called on politicians to refuse to take money from the NRA.

9. "It should not be a partisan issue to say that we do not pressure the attorney general or the FBI to use the criminal justice system as a cudgel to punish our political opponents or to explicitly call on the attorney general to protect members of our own party from prosecution because an election happens to be coming up."

Obama's more veiled attack was a reference to the President's tweet about Attorney General Jeff Sessions last Monday that also lamented the indictments of GOP Reps. Duncan Hunter and Chris Collins, suggesting they shouldn't have been charged so close to the midterm elections and because they are Republicans.

10. "It's supposed to be the party supposedly of fiscal conservatism. Suddenly deficits do not matter."

Obama slammed the Republican Party's tax reform bill passed last December, which the former President argued gave "$1.5 trillion in tax cuts to people like me, who I promise don't need it."