JOHN YANG: 100 days out from Election Day the political landscape is drastically different than it was just a little more than a week ago.

President Biden is out of the race and Vice President Kamala Harris is the presumptive Democratic nominee, that shaken up more than just the presidential race.

Effects are also being felt in the battle for the House and Senate and the fight over big issues on ballots in many states, including abortion.

Amy Walter is editor in chief of The Cook Political Report with Amy Walter.

Amy, what has this done this change the to the ticket Democratic ticket done to the Democrats chances of taking back to the house or holding on to the Senate?

AMY WALTER, The Cook Political Report with Amy Walter: Well, John, I think you have to look at it regionally and maybe even look at it state by state, district by district, what you had was a real lack of enthusiasm from the Democratic base.

I think now what you're starting to see is that that enthusiasm now is up.

And that's going to help a lot of those blue state or blue district Democrats who were worried about low turnout.

Now, if you're in -- if you're a Democrat that's still sitting in a red or purple state, it's probably mixed.

There's something about having Biden on the ticket that helped spokes who were in maybe more rural leaning areas, rural areas that they could make the case that while they disagreed with Biden, on some issues, they were not going to go that Harris's positions, on some issues, maybe just a little too much for the folks in those districts and voters in those districts.

In other words, I don't know that it changes the race for the most competitive seats in the house.

What it does do is help Democrats not lose the seats that they should be winning in.

JOHN YANG: There is a competitive race for the Senate in Pennsylvania.

And we're seeing an example of Republicans trying to define Harris as she gets in this last sprint for the race and connect her with the this -- the Senate candidates.

This is an ad from Dave McCormack, who's running against Bob Casey.

WOMAN: The nonpartisan GovTrack has rated you as the most liberal Senator.

KAMALA HARRIS, U.S. Vice President: I am prepared to get rid of the filibuster to pass a Green New Deal.

There's no question I'm in favor of banning fracking.

WOMAN: Would you ban offshore drilling?

KAMALA HARRIS: Yes.

MAN: What is the solution for voters in the fossil fuel industry?

KAMALA HARRIS: Giving the workers an ability to transition.

We're not going to treat people who are undocumented across borders criminals.

That's correct.

MAN: Raise your hand if you think it should be a civil offense rather than a fly across the border without documentation.

WOMAN: Abolish ice sounds that a position you agree with?

KAMALA HARRIS: We need to probably think about starting from scratch.

JOHN YANG: What does this add this approach?

Tell us about how Republicans are likely to dolly chair and challenge Harris, but also challenged Democratic candidates?

AMY WALTER: That's exactly right.

When I talked earlier about what difference does it make for those Democrats who sit in purple or red leaning areas, the argument would be that they now not don't have to defend just the fact that it's Democrats who are in charge in the White House with very high inflation and frustration about what's going on, on the border.

But the case is going to be made from Republicans both at the top of the ticket and in those down ballot races, that the Vice President is even more liberal than Biden, that positions she took many of the quotes in that ad came from position she took when she was running for the nomination back in 2019.

And so, that is a different challenge than if you are say somebody like Bob Casey, who was assuming that's the Democratic senator there.

He was assuming the biggest challenge with Biden was one the economy and trying to separate himself there, which he had been doing in ads.

The second and this was where Democrats were feeling it was almost untenable, which was the issue of Biden's age.

JOHN YANG: You talked earlier about the excitement on the Democratic side.

Can that excitement be sustained at this level for the next 100 days?

Or are we seeing a version of a convention bounce for the Democrats?

AMY WALTER: Yes, it's something have been enthusiasm boost.

But what I think we've known, really for months and months and months is the biggest challenge that Biden was having was with some of the traditional Democratic groups, they just did not think that Biden was either a good candidate, they weren't excited about his candidacy.

I think the fact that she's consolidated, the Democratic base is really important.

I don't think that's going to go anywhere.

I do think the challenge that Harris has, though, is that to win in those states, like Pennsylvania, you have to do more than just consolidate the base.

You have to be able to win over some of those swing voters that may be wavering right now, what is her pathway?

What is she going to be talking about when we do get to the convention that relates to the concerns of those voters who are not core democratic constituencies.

So, she's completed step one, which is get the base excited, or at least unified, be behind her candidacy?

Step number two, and this is where the convention, and the work that we're already seeing from outside Democratic groups, and I'm sure we'll see from the Harris campaign soon as well, is messaging that goes directly at the voters who are not hard partisans, but are the ones who will swing this election.

JOHN YANG: There are ballot issues in about a dozen states that are either on the ballot or trying to get on the ballot, dealing with abortion, is this change going to have any effect on that?

AMY WALTER: The folks who are trying to get Democrats elected, whether that's Kamala Harris, or down the ballot, have different strategy in some cases than those who are trying to pass these ballot initiatives.

You know, there were going to be a lot of people who vote for Donald Trump or Republican, but also vote for an amendment to protect abortion access.

We know there are a lot of pro-choice Republicans out there.

Before Biden dropped out what a lot of Democrats had hoped was that even if Biden couldn't really get the base excited, maybe some of these ballot initiatives could and that ultimately they would come to the polls, really to vote for the abortion bill or referendum, but would end up while they were they're pulling the lever for Biden.

Now I think if you've got a more revved up Democratic base, and they're going to come regardless, but I do think if you're trying to pass these initiatives, you don't want them to be connected exclusively to Democrats, because you need to win over a lot of people who are going to vote Republican.

JOHN YANG: Amy Walter, thank you very much.

AMY WALTER: You're welcome.