Washington The recent flurry of battleground state polling shows Hillary Clinton maintaining her electoral college advantage and provides some clarity to the best possible paths to 270 electoral votes for each candidate.

Since our last assessment of the state of play on the road to 270, we made some significant changes. Three of those changes have moved in Hillary Clinton's direction, but Pennsylvania -- a big electoral prize - has become more competitive at this stage of the race.

What's changed?

- Colorado (9 electoral votes) moves from "battleground" to "lean Democrat"

- Wisconsin (10 electoral votes) moves from "battleground" to "lean Democrat"

- Pennsylvania (20 electoral votes) moves from lean Democrat to "battleground"

- Utah (6 electoral votes) moves from "solid Republican" to "lean Republican"

In total, that means 19 electoral votes have moved in Hillary Clinton's direction from "battleground" to "lean Democrat" and 20 have moved toward Donald Trump with Pennsylvania's new "battleground" status, according to CNN's ratings. The 6 electoral votes in Utah have moved from solid to "lean Republican," but remain in Trump territory for now.

Road to 270: Electoral College map

The state of play

Looking at the totality of the new polling, the advertising buys, and candidate travel and organization suggests that Donald Trump's best possible path to the White House goes through the upper Midwest/Rust Belt region of the country, where he can try to turn out white working class voters in big numbers to turn states like Ohio, Pennsylvania, Michigan, and Wisconsin from blue to red. If he were able to erase Clinton's advantage in Florida (where there has been some conflicting polling of late), it would give him some incredibly important flexibility in putting together the rest of his map.

Hillary Clinton's mission remains turning out the Obama coalition (African Americans, Latinos, young people, single women) in record numbers -- especially in states where the demographics of higher turnout among those groups can really alter the outcome such as Colorado, Virginia, North Carolina, and Florida and doing so in Pennsylvania and Ohio as much as possible in order to block Trump from making significant inroads among non-college graduate whites.

The current CNN battleground map gives Hillary Clinton 236 electoral votes from states that are either solidly or leaning in her direction compared to 191 electoral votes for Donald Trump in states that are solidly or leaning in his direction. That leaves 111 electoral votes up for grabs across 8 battleground states.

The political conventions provide each candidate the perfect opportunity to set the stage for the fall campaign blitz -- both in terms of the negative frame they are building around their opponent and in terms of fleshing out their own positive attributes that get lost in the daily distortion and oversimplification that is presidential politics.

This battlefield may be set for the candidates to execute their post-convention game plans, but the news environment has been shifting rapidly and significantly. The terror attacks around the globe and at home combined with the racial strife on display in the streets of Louisiana, Minnesota and Texas have contributed to the growth of uncertainty. Voters watching the conventions will see a concentrated period of one candidate presenting herself as the steady hand running against the other candidate who is presenting himself as the much needed agent of change. It remains to be seen if the fast-moving dynamics around them will upend the demographic and structural political landscape beginning to take shape.

Solid Republican:

Alabama (9), Alaska (3), Arkansas (6), Idaho (4), Indiana (11), Kansas (6), Kentucky (8), Louisiana (8), Mississippi (6), Missouri (10), Montana (3), Nebraska (5), North Dakota (3), Oklahoma (7), South Carolina (9), South Dakota (3), Tennessee (11), Texas (38), West Virginia (5), Wyoming (3) (158 total)

Leans Republican:

Arizona (11), Georgia (16), Utah (6) (33 total)

Battleground states:

Florida (29), Iowa (6), New Hampshire (4), Nevada (6), Pennsylvania (20), Ohio (18), Virginia (13), North Carolina (15) (111 total)

Leans Democratic:

Colorado (9), Michigan (16), Wisconsin (10) (35 total)

Solid Democratic:

California (55), Connecticut (7), Delaware (3), DC (3), Hawaii (4), Illinois (20), Maine (4), Maryland (10), Massachusetts (11), New Jersey (14), New York (29), Oregon (7), Rhode Island (4), Vermont (3), Washington (12), Minnesota (10), New Mexico (5) (201 total)