Transcript for Looming showdown in Washington over Russia investigation

Next, to the looming showdown in Washington over Russia's possible role in U.S. Politics and the presidential election. At least 100 planned protests taking place across the country, calling for the truth from the current administration on Russia and other matters. This, as ex-fbi chief James Comey gets ready to testify before the senate intelligence committee next week. ABC's David Wright at the white house tonight. Reporter: Today, coast to coast -- ??? this land is my land ??? Reporter: -- A call for answers. Investigate trump! Investigate trump! Reporter: Thousands of voters, in 135 cities and towns, took part in an event called the March for truth. We're trying to send signals to our elected officials that this is important to us. Reporter: Today, some took that message straight to members of congress. When is the Republican party and you, individually, going to stand up and recognize the fact that we have, still, an adversary in the form of the Russian government? Reporter: Republican D Darrell Issa, in Orange county, insisted he's not in Vladimir Putin's pocket. Russia has been an evil empire since before Reagan coined that term, and Putin has now a decade-plus of being the evil leader. Reporter: Putin himself is defending trump, denying Russia had anything to do with meddling in the U.S. Election. Translator: Hackers can be anywhere. They can be in Russia, in Asia, even in America. Reporter: Trump said something similar back in the debates. I mean, it could be Russia. But also could be somebody sitting on their bed that weighs 400 pounds, okay? Reporter: Former FBI director James Comey may be in the position to provide some answers. This week, he's set to testify on capitol hill, breaking his silence for the first time since the president fired him. Democrats say they want to know whether the president pressured him to back off his investigation of former national security adviser Mike Flynn. Democrats say that could be obstruction of justice. And David Wright joining us live from the white house. David, we've been monitoring that emergency situation in London, and we've just learned that the president has been briefed on the incident? Reporter: That's right. Press secretary Sean spicer says the president has received an initial briefing and he'll continue to receive updates throat the night from his national security team. Remember, had E's had some strong words to say on other recent attacks in the uk, calling the prerp tray torps of the attack in Manchester evil losers. Tom? The white house monitoring the two incidents in London. David, thank you.

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